Showing papers by "National Institute of Technology, Silchar published in 2014"
TL;DR: In this article, a Two-Degree-of-freedom-Fractional Order PID (2-DOF-FOPID) controller is proposed for automatic generation control (AGC) of power systems.
172 citations
TL;DR: In this article, the authors evaluate how the conventional Savonius wind turbine performs when it rotates by the momentum of water current at low velocity from 0.3 m/s to 0.9m/s in an open water channel.
133 citations
TL;DR: In this paper, the automatic generation control of an unequal three area thermal system with single reheat turbine and generation rate constraints of 3%/min in each area was presented using a two degree of freedom (2DOF) controller called 2DOF -integral plus double derivative (IDD) as secondary controller.
129 citations
TL;DR: In this paper, a three-bladed H-rotor with unsymmetrical cambered S818 airfoil blades is investigated, which shows self-starting characteristics at many of the azimuthal angles.
113 citations
TL;DR: Simulation results suggest that proposed scheme is working satisfactorily and Lyapunov stability theory is used and required condition is derived to ensure the stability of error dynamics.
Abstract: This paper aims at synchronization and anti-synchronization between Lu chaotic system, a member of unified chaotic system, and recently developed Bhalekar–Gejji chaotic system, a system which cannot be derived from the member of unified chaotic system. These synchronization and anti-synchronization have been achieved by using nonlinear active control since the parameters of both the systems are known. Lyapunov stability theory is used and required condition is derived to ensure the stability of error dynamics. Controller is designed by using the sum of relevant variables in chaotic systems. Simulation results suggest that proposed scheme is working satisfactorily.
94 citations
TL;DR: A fractional order (FO) controller named as I(λ)D(µ) controller based on crone approximation is proposed for the first time as an appropriate technique to solve the multi-area AGC problem in power systems.
Abstract: Present work focused on automatic generation control (AGC) of a three unequal area thermal systems considering reheat turbines and appropriate generation rate constraints (GRC). A fractional order (FO) controller named as IλDµ controller based on crone approximation is proposed for the first time as an appropriate technique to solve the multi-area AGC problem in power systems. A recently developed metaheuristic algorithm known as firefly algorithm (FA) is used for the simultaneous optimization of the gains and other parameters such as order of integrator (λ) and differentiator (μ) of IλDµ controller and governor speed regulation parameters (R). The dynamic responses corresponding to optimized IλDµ controller gains, λ, μ, and R are compared with that of classical integer order (IO) controllers such as I, PI and PID controllers. Simulation results show that the proposed IλDµ controller provides more improved dynamic responses and outperforms the IO based classical controllers. Further, sensitivity analysis confirms the robustness of the so optimized IλDµ controller to wide changes in system loading conditions and size and position of SLP. Proposed controller is also found to have performed well as compared to IO based controllers when SLP takes place simultaneously in any two areas or all the areas. Robustness of the proposed IλDµ controller is also tested against system parameter variations.
85 citations
TL;DR: This paper presents the design and implementation of a simple neutral point potential (NPP) regulator for a three-level diode-clamped inverter employing a sine-triangle regulator in conjunction with a closed-loop controller with reduced switching losses.
Abstract: This paper presents the design and implementation of a simple neutral point potential (NPP) regulator for a three-level diode-clamped inverter employing a sine-triangle regulator in conjunction with a closed-loop controller with reduced switching losses. The regulator principle is based on adding a continuous variable offset voltage which regulates the midpoint potential of the dc bus. The novelty of the proposed NPP regulator is in the determination of the magnitude of variable offset voltage based upon the average value, peak-to-peak amplitude, total harmonic distortions, and third harmonic content in NPP. Aside from maintaining dc-bus voltage balance, the proposed regulator leads to a significant reduction in the voltage distortion at the NP, resulting in the reduction of the required dc-bus capacitance. It also reduces the switching losses of the inverter by inserting the “no-switching” zone within each half cycle of the fundamental voltage wave. Analytical, computer simulation, and experimental results verifying the approach are presented in this paper for various load power factor angles.
83 citations
27 Mar 2014
TL;DR: A comprehensive study of major cloud simulators is presented by highlighting their important features and analysing their pros and cons, made a comparison among the simulators by considering their important attributes and concluded with the future direction.
Abstract: Cloud computing is one of the emerging technologies with its ease of access and diverse applicability, letting customers attracted to it and thus posing many challenging issues that need to overcome in this field Since the evolution of cloud computing: Load balancing, power constrains, program offloading, cost modelling and security issues are the popular research topic in this field Deploying real cloud for testing or for commercial use is very costly Cloud simulator helps to model various kinds of cloud application by creating Data Centre, Virtual Machine and many Utilities which can be added to configure it, thus making it very easy to analyse Till now, many cloud simulators have been proposed and also available to use These simulators are built for specific purpose, and have varying features in each of them In this paper we presented a comprehensive study of major cloud simulators by highlighting their important features and analysing their pros and cons we made a comparison among the simulators by considering their important attributes and finally concluded with our future direction
80 citations
TL;DR: In this paper, the tensile and flexural tests were performed at three different speeds to study the mechanical behaviour of the composites and it was found that the mechanical property increases up to certain filler % age and then properties gradually decrease.
77 citations
TL;DR: An integrated fuzzy group decision making approach based on a fuzzy technique for order preference by similarity to the ideal solution integrated with the aggregate fuzzy weight method to rank the suppliers of a manufacturing system is presented.
Abstract: The aim of this research is to develop a quantitative approach for strategic supplier selection under a fuzzy environment in a disaster scenario. Disruption is a low probability high intensity event which causes long term system turbulence/unbalance. So resiliency planning is becoming a crucial strategic issue in the supplier selection process to keep pace with serving a globally competitive scenario. While crisp data are inadequate to model real life situations in fuzzy multiple criteria decision making, decision makers used linguistic variables to describe the importance of degrees of specific attributes. Triangular and trapezoidal linguistic data are used in determining supplier scores for various sub-criteria under general and resilient strategies, respectively. This paper presents an integrated fuzzy group decision making approach based on a fuzzy technique for order preference by similarity to the ideal solution integrated with the aggregate fuzzy weight method to rank the suppliers of a manufacturi...
76 citations
TL;DR: In this paper, the adsorption behavior of two representative pharmaceutically active compounds and widespread used drugs (ibuprofen and clofibric acid) were evaluated using a relatively abundant and inexpensive material, bamboo waste, as adsorbent prepared via ZnCl2 activation process followed by microwave heating.
Abstract: The adsorption behavior of two representative pharmaceutically active compounds and widespread used drugs (ibuprofen and clofibric acid) were evaluated using a relatively abundant and inexpensive material, bamboo waste, as adsorbent prepared via ZnCl2 activation process followed by microwave heating. The Langmuir, Freundlich, Dubunin–Raushkevich, and Temkin models were applied to describe the adsorption isotherm for the two systems. The goodness of curve fitting in the various models was done in accordance with linear regression coefficients and various error functions. The Langmuir isotherm model was applicable for describing the binding data for both ibuprofen (IBP) and clofibric acid (CA) onto activated bamboo waste (ABW) with the following order of adsorption capacity: IBP (278.55 mg·g–1) > CA (229.35 mg·g–1). The Gibbs free energy of −6.15 and −5.56 kJ mol–1 estimated for IBP and CA onto ABW unravelled the spontaneous nature of this adsorbent toward these adsorbates. Both pH and temperature exhibited...
TL;DR: In this article, a methodology to evaluate optimum material for engineering design using an integrated approach, in which criteria weights are computed using the entropy method and ranking of the alternatives is computed using TOPSIS (Technique for order performance by similarity to ideal solution).
TL;DR: In this paper, the automatic generation control of an autonomous hybrid energy system based on organic Rankine cycle solar-thermal technology is investigated, where the authors consider the frequency excursion problem.
Abstract: The organic Rankine cycle solar–thermal power system is a promising concept for the distributed energy market. The present work investigates the automatic generation control of an autonomous hybrid energy system based on organic Rankine cycle solar–thermal technology. Any mismatch between the active power generation and consumption in the hybrid energy system manifests itself as a frequency deviation from the nominal system frequency. To confront the frequency excursion problem, the present work considers auto
TL;DR: In this article, the authors report an efficient, mild and convenient synthetic protocol for the C-S cross-coupling reaction of various aryl, benzyl, allyl chlorides and thiols using 5-mol-% Nickel-Schiff base catalyst with NaOH as the base, in DMF at 70°C.
TL;DR: In this article, a two-level evaluation framework is proposed to assess the design from a process planning perspective for additive manufacturing processes, and several indicators for assessment are defined and used to convey the information from process planning for improving the design.
TL;DR: In this paper, the influence of powder metallurgical (P/M) electrodes on the surface of mild steel in electric discharge machining was described, and an attempt has been made to deposit a uniform layer of tungsten and its carbide over the mild steel substrate using P/M green compact tools by electric discharge coating process.
Abstract: This paper describes the influence of powder metallurgical (P/M) electrodes on the surface of mild steel in electric discharge machining. An attempt has been made to deposit a uniform layer of tungsten and its carbide over the mild steel substrate using P/M green compact tools by electric discharge coating process. In this experimental work, W and Cu powders of 325 mesh size have been selected as electrode material and mild steel as workpiece material. A detailed investigation of process parameters, such as composition, compaction load, current, on-time, and off-time, which influence the material transfer rate (MTR), tool wear rate, roughness, and layer thickness, has been performed. Highest MTR of 281 mg/min and LT of 1262.99 µm have been achieved successfully. The hardness of deposited layer has been measured which proves that the deposited layer is 5–6 times harder than the substrate material.
TL;DR: In this paper, a small signal stability analysis of an autonomous hybrid energy system with dish-Stirling solar thermal systems (DSTS) in integration with diesel engine generators (DEG), fuel cells (FC), battery energy storage system (BESS), and aqua electrolyzer (AE).
TL;DR: A new theorem on the degree of approximation of function f ∼, conjugate to a 2 π periodic function f belonging to the generalized weighted Lipschitz W ( L r, ξ ( t ) ) ( r ⩾ 1 ) -class by dropping the monotonicity condition on the generating sequence { p n } has been established.
TL;DR: In this article, the experimental data were analyzed using Taguchi optimization method and the optimal settings of the process parameters for load, tensile and flexural stress were determined, and the optimized sets of values of various parameters were depicted.
TL;DR: In this article, an analytical model for the determination of temperature distribution, fin efficiency and optimum design parameters of a porous moving fin which is losing heat by simultaneous convection and radiation to its surroundings is proposed.
TL;DR: In this paper, a simple method for the preparation of silver nanoparticles (Ag NPs) using saturated fatty acid and tryptophan as capping and reducing agent, respectively, was established for the first time.
Abstract: In the present study, we established for the first time a simple method for the preparation of silver nanoparticles (Ag NPs) using saturated fatty acid and tryptophan as capping and reducing agent, respectively. The -NH2 group of tryptophan and the carboxylate group of saturated long chain carboxylate endow them as reducing and stabilising property respectively. The -NH2 group of the tryptophan reduced the Ag+ ions while the carboxylate group bounded strongly to the surface of the nanoparticles (NPs). This approach is a very special, size controlled synthetic approach for the large-scale synthesis of Ag NPs. The sizes of the synthesised Ag NPs were controlled by varying the processing parameters, such as reaction time and the chain length of the silver carboxylate (C12–C16). Studies showed that the particle size of Ag NPs increases with increase in reaction time and carbon chain length. The synthesised Ag NPs were characterized by ultra-violet spectroscopy (UV–vis), transmission electron spectroscopy (TEM), selected area electron diffraction (SAED), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The synthesised Ag NPs was used to evaluate the photo catalytic degradation of the methyl violet 6B dye under solar irradiation. The efficiency and rate of photo degradation of methyl violet 6B dye were also studied.
TL;DR: A straightforward, efficient, and selective oxidation of sulfide to sulfoxide with 30% H2O2 catalyzed by copper(II)-Schiff base complex is described in this paper.
TL;DR: In this article, the role of cationic and non-ionic surfactants, namely cetyl pyridinium chloride (CPC) and triton X-100, in the synthesis of SnO2 nanoparticles is investigated.
Abstract: A green synthesis of SnO2 nanoparticles was successfully developed using urea by a microwave heating method. This method resulted in the formation of spherical, microcrystalline SnO2 nanoparticles with an average size of ∼4.0 nm. The role of cationic and non-ionic surfactants, namely cetyl pyridinium chloride (CPC) and triton X-100, in the synthesis of SnO2 nanoparticles are investigated. In this reaction, surfactants act as capping agents. The addition of a surfactant along with urea leads to the formation of spherical and microcrystalline SnO2 nanoparticles. The average particle size of the CPC assisted SnO2 nanoparticles is ∼4.5 nm, while that of triton X-100 assisted SnO2 nanoparticles is ∼5.8 nm. An increase in band gap energy is observed with a decrease in particle size because of three dimensional quantum confinement effect shown by synthesized SnO2 nanoparticles in their electronic spectra. The band gap energy of SnO2 nanoparticles synthesized using urea is ∼4.30 eV, whereas that of CPC assisted SnO2 nanoparticles and triton X-100 assisted SnO2 nanoparticles are ∼4.25 and ∼4.15 eV, respectively. The synthesized SnO2 nanoparticles were characterized by transmission electron microscopy (TEM), selected area electron diffraction (SAED) and Fourier transformed infrared spectroscopy (FT-IR). The optical properties were investigated using UV-visible spectroscopy. The synthesized SnO2 nanoparticles act to be an efficient photocatalyst in the degradation of rhodamine B and methyl violet 6B dye under direct sunlight. For the first time, methyl violet 6B and rhodamine B dye were degraded by solar irradiation using SnO2 nanoparticles as catalyst.
TL;DR: In this article, an integer-order based, two-degree-of-freedom Proportional plus Integral plus Double Derivative (2-DOF-PIDD) controller was proposed for automatic generation control of a three unequal area thermal system considering reheat turbines and appropriate generation rate constraints.
08 Apr 2014
TL;DR: This paper will give a review of various challenges in this field and measures to overcome such in the security policies of mobile cloud computing.
Abstract: With an explosive growth of the mobile applications and emerging of cloud computing concept, the Mobile Cloud Computing (MCC) has become a potential technology for the mobile service users. MCC integrates the technology of cloud computing with mobile environment and has taken part of major discussion thread in the IT world since 2009. The ABI Research predicts that the number of mobile cloud computing subscribers is expected to grow from 42.8 million (1.1% of total mobile users) in 2008 to 998 million (19% of total mobile users) in 2014. Despite of this hype achieved by mobile cloud computing, the growth of mobile cloud computing subscribers is still below expectations. According to the recent survey conducted by the International Data Corporation, most IT Executives and CEOs are not interested in adopting such services due to the drawbacks associated with this (e.g., battery life, storage, and bandwidth), environment (e.g., heterogeneity, scalability, and availability), and security (e.g., reliability and privacy). In spite of various efforts to overcome these, there are a number of loopholes and challenges that still exist in the security policies of mobile cloud computing. This paper will give a review of various challenges in this field and measures to overcome such.
TL;DR: In this paper, a new formulation to maximize the operational profit of a micro grid connected hybrid system having wind farm and pumped storage unit for a day ahead electricity market in a frequency based pricing environment is presented.
TL;DR: In this article, a fuzzy analytic hierarchy process is used to calculate the relative importance of various NTM processes taking product and process characteristics as the comparison basis, and an overall score of various non-traditional machining processes have been obtained using quality function deployment methodology based on various shape features and work material combination.
Abstract: With the advancement in material science and engineering, hard as well as difficult to cut materials are coming to the fore on regular basis Machining such advanced materials with higher geometrical accuracy by conventional means is almost impossible Thus, demand for higher accuracy with desired surface finish leads us to a large pool of non-traditional machining (NTM) processes However, zeroing-in for a particular NTM process, for a particular operation and for a case-specific machining, is a cumbersome task In order to make this task simpler for a decision-maker, the present research uses, fuzzy analytic hierarchy process to calculate the relative importance of various NTM processes taking product and process characteristics as the comparison basis Finally, an overall score of various NTM processes have been obtained using quality function deployment methodology based on various shape features and work material combination Also, the variations in the process capability features have been taken int
TL;DR: A cleaner, greener, cheaper and environment friendly method for the generation of self assembled silver nanoparticles (Ag NPs) applying a simple irradiation technique using the aqueous extract of the fish scales of Labeo rohita is described.
TL;DR: In this paper, the effect of process parameters on surface roughness and kerf width of aluminum and mild steel are investigated and single objective taguchi method is used for process parameter optimization.
TL;DR: In this paper, a single step, mild, environmentally friendly green method has been developed for the synthesis of physiologically active 3,4-dihydropyrimidin-2-(1H)-ones employing L-tyrosine as catalyst under solvent-free conditions at room temperature via grinding.
Abstract: A single step, mild, environmentally friendly green method has been developed for the synthesis of physiologically active 3,4-dihydropyrimidin-2-(1H)-ones employing L-tyrosine as catalyst under solvent-free conditions at room temperature via grinding. The procedure is efficient, time saving and gives high-yields. The structures and purity of these compounds were confirmed by FT-IR, NMR (1H and 13C) and HRMS spectral analysis. DFT calculations have been used to show the effectiveness of L-tyrosine as a suitable catalyst for the above reaction.