NERIST

Nirjuli, India
Nirjuli, India

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Wahengbam M.,NERIST | Marchang N.,NERIST
Proceedings - 2012 3rd National Conference on Emerging Trends and Applications in Computer Science, NCETACS-2012 | Year: 2012

Mobile Ad hoc network (MANET) is a new paradigm in wireless revolution, which is a self-configured network of wireless mobile nodes. Due to proliferation of miniature yet powerful mobile computing devices, it is gaining acceptance and popularity. However, MANET is vulnerable to security attacks due to its inherent characteristics such as dynamic topology, lack of a centralized coordinator and open wireless channel. In this paper, we analyze some security attacks of MANET and we propose to identify the attack by using an Intrusion Detection System (IDS). The proposed IDS uses fuzzy logic to detect malicious behavior and identify the attacks. © 2012 IEEE.


Chanu Y.J.,NERIST | Tuithung T.,NERIST | Manglem Singh Kh.,NIT Manipur
Proceedings - 2012 3rd National Conference on Emerging Trends and Applications in Computer Science, NCETACS-2012 | Year: 2012

The paper describes a short survey on different types of steganography techniques for image in spatial and transform domains and steganalysis techniques for the detection of secret message in the image. The strong and weak points of these techniques are mentioned briefly so that researchers who work in steganography and steganalysis gain prior knowledge in designing these techniques and their variants. One can develop a better steganography technique by analyzing the contemporary steganalysis techniques. © 2012 IEEE.


Hazarika N.,NERIST | Saikia M.,NERIST
2014 International Conference on Signal Processing and Integrated Networks, SPIN 2014 | Year: 2014

Transmitted images may have many different applications like commercial, military, medical etc. 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 selective encryption techniques using spatial or DCT domain. The result of the several experimental, statistical analysis and sensitivity test shows that the proposed image encryption scheme provides an efficient and secure way for real-time image encryption and transmission. A chaotic logistic map is used to perform different encryption/decryption operation in this proposed method. © 2014 IEEE.


Singh T.J.,NERIST | Samanta S.,NERIST
Materials Today: Proceedings | Year: 2015

In recent years, the interest of using the fiber reinforced composites (FRCs) has increased due to its potential for replacing the traditional materials in various applications. Kevlar fiber, due to its unique properties such as higher strength to mass ratio and modulus, has become very popular as reinforcement in composite materials and its application has growth considerably. However, for enhancing its properties in various applications, a proper characterization is very important. Many researches have been conducted in recent years, for characterization of Kevlar fiber and its composites. In this paper, a state-of-the art review of these characterizations is presented. © 2015 Elsevier Ltd.


Tiwari V.K.,Junagadh Agricultural University | Pandey K.P.,Indian Institute of Technology Kharagpur | Pranav P.K.,NERIST
Journal of Terramechanics | Year: 2010

A variety of methods, ranging from theoretical to empirical, which have been proposed for predicting and measuring soil-vehicle interaction performance are reviewed. A single wheel tyre testing facility at Indian Institute of Technology, Kharagpur, India, was used to check the applicability of the most widely used traction models, for tyres used in Indian soil conditions. Finally, the coefficients of traction prediction equations developed by Brixius [16] were modified to fit traction data obtained from the testing of the tyres in the Indian soil conditions. © 2010 ISTVS. Published by Elsevier Ltd.


In this work, the shape optimization of a single link revolute-jointed flexible manipulator is carried out. Manipulator link is considered as a Euler-Bernoulli beam and finite element based on Lagrange approach is employed for dynamic analysis. Sequential quadratic programming (SQP) method is applied to extremize the objective functions. Four different optimization problems are solved for comparative study of the model for vibration suppression. © 2013 Elsevier Ltd.


Maheshwari B.K.,Indian Institute of Technology Roorkee | Singh H.P.,NERIST | Saran S.,Indian Institute of Technology Roorkee
Journal of Geotechnical and Geoenvironmental Engineering | Year: 2012

A study on liquefaction resistance of Solani sand reinforced with geogrid sheet, geosynthetic fiber, and natural coir fiber is reported. Tests were carried out on shake table (vibration table) with sand samples prepared at a relative density of 25%, with and without reinforcements. Synthetic geogrid sheets were used in three different combinations of three, four, and five layers. In case of fibers, the percentage of fibers by weight of dry sand were taken as 0.25, 0.50, and 0.75% and mixed randomly with the sand sample. Theliquefaction parameters, such as the maximum pore water pressure (Umax), maximum pore water pressure built-up time, stay time for Umax, and pore water pressure dissipation time were measured corresponding to various levels of accelerations varying from 0.1-0.4 g. Thefrequency of the dynamic load was kept constant at 5 Hz. The liquefaction resistance of sand was evaluated in terms of maximum pore water pressure ratio (ru max). Test results indicated that on inclusion of fibers and geogrid sheets into the sand samples, the ru max decreased. On increasing the fiber content and number of geogrid sheets, ru max decreasedfurther, and this decrease is significant at a small amplitude of excitation. The averageincrease in liquefaction resistance of sand reinforced with synthetic and coir fibers wasfound to be 88 and 91%, respectively, for 0.75% fiber content, whereas for five layers ofgeogrid sheets, this increase was about 31% at 0.1 g acceleration. © 2012 American Society of Civil Engineers.


Sivakumar P.,NERIST | Prasad R.K.,NERIST
Water Resources Management | Year: 2014

Pressure deficient condition occurs in the water distribution network (WDN) when the nodal demands are in excess of the design discharge as in the case of fire demand, pump failure, pipe breaks, valve failure etc. It causes either no-flow or partial-flow depending upon the available pressure head at the nodes. To evaluate the nodal flows in such condition, node flow analysis (NFA) gives reasonable results in comparison to demand-driven analysis (DDA) and head-dependent analysis (HDA). The NFA works on the predefined pressure-discharge relationship to evaluate the nodal flows. However, this approach requires human intervention and hence cannot be applied to large WDN. Recently, modified pressure-deficient network algorithm (M-PDNA) has been developed by Babu and Mohan (2012) for pressure-deficient analysis with EPANET toolkit. However, it requires modification of the source code of EPANET. In this study a relationship with the M-PDNA and node flow analysis (Gupta and Bhave 1996) has been investigated and it is found that M-PDNA is the simplified version of NFA. Further, the working principle of M-PDNA has been investigated with suitable examples of Babu and Mohan (2012). The theoretical basis of M-PDNA has not been investigated in terms of head-discharge relationship. Herein, a head-discharge relationship based on the working principal of M-PDNA is proposed. Some of the toolkits are also readily available to modify demand driven solver of EPANET 2 to suit for the pressure-driven analysis and then it can be used for analysing pressure deficient network. Also in this study, a modification in M-PDNA approach is proposed which does not require the use of EPANET toolkit which is found to be capable of simulating both pressure-sufficient and pressure-deficient conditions in a single hydraulic simulation. Using the proposed approach, pressure-deficient condition is analysed with constant and variable demand pattern. © 2014 Springer Science+Business Media Dordrecht.


Singh A.D.,NERIST | Subadar R.,NEHU
AEU - International Journal of Electronics and Communications | Year: 2014

An expression for the probability distribution function (PDF) of the signal-to-noise ratio of a selection combining receiver in two-wave with diffuse power fading channel is derived. Using this PDF expression, the capacity for the different adaptive transmission techniques employing selection combining (SC) are obtained. The study presents the effects of the ratio of total dominant signal power to the scattered signal power on the system capacity. The change in the capacity of the system with the diversity order for a SC receiver in the fading channel is also presented. © 2013 Elsevier GmbH.


Sivakumar P.,NERIST | Prasad R.K.,NERIST
Water Resources Management | Year: 2015

Generally, the water distribution networks are designed for peak demands so that under normal operating conditions pressure is adequate to meet the nodal demand however, due to this, the pressure remains excessive when the consumption is low. This leads to huge water leakages and pipe bursts due to excess available pressure. These excess of pressure can be reduced by operating pressure reducing valves. Moreover, the pressure deficient conditions of water distribution network depends on many factors such as excess demand (i.e., fire fighting demand), location and elevation of nodes, location and pressure setting values of pressure reducing valve, ageing of pipes (i.e., increase the pipe roughness) etc. In exceptional situations, pressure deficient condition also may occur when there is a fire demand while pressure reducing valves are in operating condition. The available literature of the pressure deficient condition as well as optimal location, number and their pressure setting values of pressure reducing valves are analysed by mathematical programming or optimization methods. Normally, it is cumbersome to the field engineers to use the any toolkit utility functions. Hence in this study, the pressure deficient condition is analysed via the method of modified pressure-deficient network algorithm without using EPANET toolkit functions which are coupled with pressure reducing valve operation. A benchmark problem is analysed and compared for the proposed method. Further, a real water distribution networks is analysed introducing fire demand at junction/distribution node using fixed and diurnal nodal demand pattern coupled with and without pressure reducing valve operation in a single hydraulic simulation. © 2014, Springer Science+Business Media Dordrecht.

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