North Eastern Regional Institute of Science and Technology

About: North Eastern Regional Institute of Science and Technology is a education organization based out in Itanagar, India. It is known for research contribution in the topics: Population & Raman spectroscopy. The organization has 813 authors who have published 1429 publications receiving 16122 citations.

A wavelet based partial image encryption using chaotic logistic map

Abstract: Transmitted images may have many different applications like commercial, military and medical. To protect the information from unauthorized access secure image transfer is required and this can be achieved by image data encryption. But the encryption of whole image is time consuming. This paper proposed a partial encryption technique using DWT domain, pixel shuffling and modification of pixel values. The result of the several experimental, statistical analysis and sensitivity test show that the proposed image encryption scheme provides an efficient and secure way for real-time image encryption and transmission.

Flood Inundation Modeling Using Nakagami- m Distribution Based GIUH for a Partially Gauged Catchment

Abstract: Flood inundation extent is highly dependent on intensive rainfall and topography of floodplain. This paper presents a study to develop a flood inundation model for partially gauged upper Ganga catchment. For design flood computations, 100-year return period of 1 h duration rainfall is adopted. This is obtained by intensity duration frequency (IDF) relationship based on Self Recording Rain Gauge (SRRG) data of the study area. The SCS-CN method is used for rainfall excess computations. The Nakagami-m distribution has been used to compute Geomorphological Instantaneous Unit Hydrograph (GIUH) of different sub-catchments of upper Ganga river system because of non-availability of observed hydrograph. Routing of the hydrograph has been done by the Kinematic Wave (KW) approach. KW equations have been solved through Preissmann implicit method. The most sensitive KW parameters (i.e. overland roughness and channel roughness) have been estimated for a stretch on river Bhagirathi, a tributary of river Ganga. Nakagami-m distribution based GIUHs have been fed at the upper (i.e. input to the proposed model) as well as at downstream point (i.e. output to the proposed model) of that river stretch. Consequently, KW parameters have been calibrated by comparing the computed hydrograph with output hydrograph. Validation of estimated KW parameters has been carried out in the catchment of river Alaknanda which is another significant tributary of river Ganga. Thereafter, adopted KW parameters have been applied to calculate the design flood peak at the outlet of study area i.e. downstream of Haridwar city. Computations of overtopping water above the natural levees downstream of Haridwar city have been carried out considering the levee as broad crested weir. Topographic features of the floodplain have been obtained from freely available Shuttle Radar Topography Mission (SRTM) data. Finally, extents of submerged areas in different flood hours corresponding to design rainfall have been developed by ArcGIS 9.2 software.

Estimation of arrhythmia episode using variational mode decomposition technique

Abstract: Detection of life threatening arrhythmia like ventricular flutter (VFL) or ventricular tachycardia (VT) and atrial flutter (AFL) at the earlier stage may save life by defibrillation therapy. Different type of mechanism has been proposed earlier in time domain or by spectral analysis of ECG signal. In this work a frequency domain approach is proposed by spectral decomposition of ECG signal. Spectral decomposition of signal is done with the help of variational mode decomposition (VMD) technique. VMD model is used to obtain the required number of spectral mode of the test signal and their central mode of oscillation. This central frequency of decomposed signal and maximum phase change within a specified window are used to characterize ventricular tachycardia and atrial flutter and compared to normal rhythms by K-near neighbour (KNN) classification method. Accuracy of 98.6% is obtained for VT classification. The proposed method eliminates the requirement of detecting fiducial points of ECG signal as necessary in conventional classification methods.

Synthesis, Characterization and Thermal Decomposition of M1[M2(C2O4)2]xH2O (x=5 for M1=Co and x=4 for M1=Cd; M2=Ni)

Abstract: Cobalt bis(oxalato)nickelate pentahydrate, Co[Ni(C2O4)2]5H2O and cadmium bis(oxalato)nickelate tetrahydrate, Cd[Ni(C2O4)2]4H2O have been synthesized and characterized by elemental analysis, reflectance and IR spectral studies. Thermal decomposition studies (TG, DTG and DTA ) in air showed that both the compound of cobalt and cadmium produced the oxide, MNiOx (x=3 for M=Co; x=2 for M=Cd ) at 325 and 360°C respectively. DSC studies in nitrogen attributed only the mixture of both the metal at the end.

Assessment of Antioxidant Activity of Six Ficus Species—Underutilized Fruits from Arunachal Pradesh in North East India

Abstract: The fruits of six Ficus species, including F. auriculata Lour., F. maclellandii King., F. hirta Vahl., F. nervosa Heyne ex. Roth., F. racemosa Linn., and F. semicordata Buch-Ham.ex. Roth, are traditionally consumed by local people in North East India. The fruits were studied for their total phenolic content (TPC) and total flavonoid content (TFC). The 90% ethanolic extract of the fruits were screened for potential antioxidant capacity by employing different in vitro assays like ABTS•+ (2,2-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid), FRAP (ferric reducing antioxidant power), DPPH• (2,2′-diphenyl-1-picryl hydrazyl) scavenging activity, hydrogen peroxide radical scavenging activity, hydroxyl radical scavenging activity, chelating power, and reducing power properties. Extract from F. maclellandii and F. racemosa showed higher antioxidant activity in all of the systems than other species. It was concluded that these two species are promising sources of natural dietary antioxidants. According to statis...