Showing papers by "Indian Institute of Technology Guwahati published in 2014"
TL;DR: It is explained how several long-standing assumptions about cellular networks need to be rethought in the context of a load-balanced HetNet: these are highlighted as three deeply entrenched myths that are then dispel.
Abstract: Matching the demand for resources (?load?) with the supply of resources (?capacity?) is a basic problem occurring across many fields of engineering, logistics, and economics, and has been considered extensively in both the Internet and wireless networks. The ongoing evolution of cellular communication networks into dense, organic, and irregular heterogeneous networks (HetNets) has elevated load awareness to a central problem, and introduces many new subtleties. This article explains how several long-standing assumptions about cellular networks need to be rethought in the context of a load-balanced HetNet: we highlight these as three deeply entrenched myths that we then dispel. We survey and compare the primary technical approaches to HetNet load balancing: (centralized) optimization, game theory, Markov decision processes, and the newly popular cell range expansion (a.k.a. biasing), and draw design lessons for OFDMA-based cellular systems. We also identify several open areas for future exploration.
524 citations
TL;DR: In this article, the authors presented a search for a dark photon in the reaction e^{+}e^{-}→γA^{'], A^{'}→e''+''e''-e''−γA''−E''−μ'' −μ'' -E'' −γA''.
Abstract: Dark sectors charged under a new Abelian interaction have recently received much attention in the context of dark matter models. These models introduce a light new mediator, the so-called dark photon (A^{'}), connecting the dark sector to the standard model. We present a search for a dark photon in the reaction e^{+}e^{-}→γA^{'}, A^{'}→e^{+}e^{-}, μ^{+}μ^{-} using 514 fb^{-1} of data collected with the BABAR detector. We observe no statistically significant deviations from the standard model predictions, and we set 90% confidence level upper limits on the mixing strength between the photon and dark photon at the level of 10^{-4}-10^{-3} for dark photon masses in the range 0.02-10.2 GeV. We further constrain the range of the parameter space favored by interpretations of the discrepancy between the calculated and measured anomalous magnetic moment of the muon.
436 citations
TL;DR: The physics of the SLAC and KEK B Factories are described in this paper, with a brief description of the detectors, BaBar and Belle, and data taking related issues.
Abstract: This work is on the Physics of the B Factories. Part A of this book contains a brief description of the SLAC and KEK B Factories as well as their detectors, BaBar and Belle, and data taking related issues. Part B discusses tools and methods used by the experiments in order to obtain results. The results themselves can be found in Part C.
413 citations
TL;DR: In this paper, food waste with high decomposition potential can be successfully digested anaerobically for the production of biogas, which can be used for electricity production and the final digested sludge as a fertilizer.
Abstract: Food waste with high decomposition potential can be successfully digested anaerobically for the production of biogas. As the fossil-fuel reserves decline anaerobic digestion can be a better alternative as a renewable energy source. The byproducts such as biogas with 50–60% methane content can be efficiently used for electricity production and the final digested sludge as a fertilizer. Even though anaerobic digestion is a proven technology, still there exist some technical difficulties (organic loading rate, solid retention time, biogas composition, specific gas production) and scientific understandings (carbon to nitrogen ratio, volatile fatty acids production, pH variation, nutrient concentration) in operating reactors for solid organic wastes. First the paper gives an overview of certain fundamental aspects of anaerobic digestion considered important for the digestion of food waste and its biochemical reactions. Then it describes food waste as the substrate for anaerobic digestion and its optimal conditions for the increased activity of biogas production. Finally it has been reviewed about the performance of the different pre-treatment methods and anaerobic reactor configurations in the digestion of food waste for increasing methane content in the biogas.
268 citations
TL;DR: The NDV based recombinant vaccine offers a pertinent choice for the construction of live attenuated vaccine due to its modular nature of transcription, minimum recombination frequency, and lack of DNA phase during replication.
252 citations
TL;DR: It was found that the Fuzzy Logic and LS-SVR approaches can be employed successfully in modeling the daily evaporation process from the available climatic data, and results showed that the machine learning models outperform the traditional HGS and SS empirical methods.
Abstract: This paper investigates the abilities of Artificial Neural Networks (ANN), Least Squares – Support Vector Regression (LS-SVR), Fuzzy Logic, and Adaptive Neuro-Fuzzy Inference System (ANFIS) techniques to improve the accuracy of daily pan evaporation estimation in sub-tropical climates. Meteorological data from the Karso watershed in India (consisting of 3801 daily records from the year 2000 to 2010) were used to develop and test the models for daily pan evaporation estimation. The measured meteorological variables include daily observations of rainfall, minimum and maximum air temperatures, minimum and maximum humidity, and sunshine hours. Prior to model development, the Gamma Test (GT) was used to derive estimates of the noise variance for each input–output set in order to identify the most useful predictors for use in the machine learning approaches used in this study. The ANN models consisted of feed forward backpropagation (FFBP) models with Bayesian Regularization (BR), along with the Levenberg–Marquardt (LM) algorithm. A comparison was made between the estimates provided by the ANN, LS-SVR, Fuzzy Logic, and ANFIS models. The empirical Hargreaves and Samani method (HGS), as well as the Stephens–Stewart (SS) method, were also considered for comparison with the newer machine learning methods. The Root Mean Square Error (RMSE) and Correlation Coefficient (CORR) were the statistical performance indices that were used to evaluate the accuracy of the various models. Based on the comparison, it was found that the Fuzzy Logic and LS-SVR approaches can be employed successfully in modeling the daily evaporation process from the available climatic data. In addition, results showed that the machine learning models outperform the traditional HGS and SS empirical methods.
232 citations
TL;DR: In this paper, the effect of compression ratio on the performance, combustion and emission characteristics of a dual fuel diesel engine run on raw biogas was investigated, where a 3.5-kW single cylinder, direct injection, water cooled, variable compression ratio diesel engine is converted into a biogAS run dual-fuel diesel engine by connecting a venturi gas mixer at the manifold.
226 citations
TL;DR: An adaptive second order terminal sliding mode (SOTSM) controller is proposed for controlling robotic manipulators where instead of the normal control input, its time derivative is used in the proposed controller.
Abstract: In this paper an adaptive second order terminal sliding mode (SOTSM) controller is proposed for controlling robotic manipulators. Instead of the normal control input, its time derivative is used in the proposed controller. The discontinuous sign function is contained in the derivative control and the actual control obtained after integration is continuous and hence chatterless. An adaptive tuning method is utilized to deal with the system uncertainties whose upper bounds are not required to be known in advance. The performance of the proposed control strategy is evaluated through the control of a two-link rigid robotic manipulator. Simulation results demonstrate the effectiveness of the proposed control method.
222 citations
TL;DR: Highly fluorescent copper nanoclusters synthesized using single-step reduction of copper sulfate by hydrazine in the presence of lysozyme were found to be stable between pH 4 and 10 and in addition having excellent chemical and photostability.
Abstract: Highly fluorescent copper nanoclusters (Cu NCs) have been synthesized using single-step reduction of copper sulfate by hydrazine in the presence of lysozyme. The fluorescence quantum yield was measured to be as high as 18%. The emission was also found to be dependent on the excitation wavelength. Mass spectrometric analyses indicated the presence of species corresponding to Cu2 to Cu9. Transmission electron microscopic analyses indicated the formation of agglomerated particles of average diameter of 2.3 nm, which were constituted of smaller particles of average diameter of 0.96 nm. They were found to be stable between pH 4 and 10 and in addition having excellent chemical and photostability. The noncytotoxic NCs were used to successfully label cervical cancer HeLa cells.
184 citations
TL;DR: In this article, the experimental data were fitted with isotherm models like Langmuir and Freunlich isotherms, and the thermodynamics parameters were calculated and found to be exothermic in natures for all three adsorbents.
Abstract: Combustion of fossil fuels is one of the major sources of greenhouse gas (GHG) CO2, it is therefore necessary to develop technologies that will allow us to utilize the fossil fuels while reducing the emissions of GHG. Removal of CO2 from flue gasses has become an effective way to mitigate the GHG and adsorption is considered to be one of the methods. Adsorption of CO2 on zeolite 13X, zeolite 4A and activated carbon (AC) have been investigated at a temperature ranging from 25 to 60 °C and pressure up to 1 bar. The experimental data were fitted with isotherm models like Langmuir and Freunlich isotherm model. The Langmuir model fit well with the two zeolites and Freunlich model fit well with AC. The thermodynamics parameters were calculated and found to be exothermic in natures for all three adsorbents. Moreover, regeneration studies have been conducted in order to verify the possibility of activated carbon reutilization, to determine its CO2 adsorption capacity within consecutive cycles of adsorption–desorption. Temperature swing adsorption was employed as the regeneration method through heating up to a temperature of approximately 100 °C. There is no full reversibility for zeolites while AC can achieve complete regenerations.
165 citations
TL;DR: In this paper, an amplitude analysis of B-0 --> J/psi K-pi(+) decays to a new charged charmonium-like state Z(c)(4200)(+) decaying to J(psi pi(+) with a significance of 6.2 sigma.
Abstract: We present the results of an amplitude analysis of B-0 --> J/psi K- pi(+) decays. A new charged charmoniumlike state Z(c)(4200)(+) decaying to J/psi pi(+) is observed with a significance of 6.2 sigma. The mass and width of the Z(c)(4200)(+) are 4196(-29-13)(+31+17) MeV/c(2) and 370(-70-132)(+70+70) MeV, respectively; the preferred assignment of the quantum numbers is J(P) = 1(+). In addition, we find evidence for Z(c)(4430)(+) --> J/psi pi(+). The analysis is based on a 711 fb(-1) data sample collected by the Belle detector at the asymmetric-energy e(+)e(-) collider KEKB.
01 Feb 2014
TL;DR: A vision based intelligent algorithm to detect driver drowsiness makes use of features learnt using convolutional neural network so as to explicitly capture various latent facial features and the complex non-linear feature interactions.
Abstract: The advancement of computing technology over the years has provided assistance to drivers mainly in the form of intelligent vehicle systems. Driver fatigue is a significant factor in a large number of vehicle accidents. Thus, driver drowsiness detection has been considered a major potential area so as to prevent a huge number of sleep induced road accidents. This paper proposes a vision based intelligent algorithm to detect driver drowsiness. Previous approaches are generally based on blink rate, eye closure, yawning, eye brow shape and other hand engineered facial features. The proposed algorithm makes use of features learnt using convolutional neural network so as to explicitly capture various latent facial features and the complex non-linear feature interactions. A softmax layer is used to classify the driver as drowsy or non-drowsy. This system is hence used for warning the driver of drowsiness or in attention to prevent traffic accidents. We present both qualitative and quantitative results to substantiate the claims made in the paper.
TL;DR: This work investigates the dynamical behavior of continuous and discrete Schrödinger systems exhibiting parity-time (PT) invariant nonlinearities and identifies the PT-symmetry-breaking conditions.
Abstract: odinger systems exhibiting parity-time (PT) invariant nonlinearities. We show that such equations behave in a fundamentally different fashion than their nonlinear Schr¨ odinger counterparts. In particular, the PT-symmetric nonlinear Schr¨ odinger equation can simultaneously support both bright and dark soliton solutions. In addition, we study a discretized version of
TL;DR: In this article, an interconnected power system with multi-source power generation is proposed for load frequency control (LFC) in deregulated power environment, which uses less number of state variables for feedback as measurement of all of the state variables of a large system is impossible in the real world.
TL;DR: In this article, a poreexpanded MCM-41 was used for CO 2 capture and the experimental data of CO 2 uptake as a function of time at different pressure and temperature conditions were analyzed by both pseudo-first order and pseudo-second order kinetic models.
TL;DR: The paper surveys algorithms to implement such sampling efficiently, with particular focus on the case of constrained devices with small on-board storage and without access to large numbers of external random bits.
Abstract: Modern lattice-based public-key cryptosystems require sampling from discrete Gaussian (normal) distributions. The paper surveys algorithms to implement such sampling efficiently, with particular focus on the case of constrained devices with small on-board storage and without access to large numbers of external random bits. We review lattice encryption schemes and signature schemes and their requirements for sampling from discrete Gaussians. Finally, we make some remarks on challenges and potential solutions for practical lattice-based cryptography.
TL;DR: In this paper, the combustion and pyrolysis of brown coal using reactive molecular dynamic (MD) simulation was studied and it was found that the effects of densities are lesser as compared to temperature.
TL;DR: A copper-catalyzed cross-dehydrogenative coupling strategy has been developed for the synthesis of two classes of esters from simple solvents, which resulted in α-acyloxy ethers and allyl esters.
TL;DR: In this paper, the microscopic origin of lattice expansion and contraction in undoped rutile TiO2 nanostructures was investigated by employing several structural and optical spectroscopic tools.
Abstract: We have investigated the microscopic origin of lattice expansion and contraction in undoped rutile TiO2 nanostructures by employing several structural and optical spectroscopic tools. Rutile TiO2 nanostructures with morphologies such as nanorods, nanopillars and nanoflowers, depending upon the growth conditions, are synthesized by an acid-hydrothermal process. Depending on the growth conditions and post-growth annealing, lattice contraction and expansion are observed in the nanostructures and it is found to correlate with the nature and density of intrinsic defects in rutile TiO2. The change in lattice volume correlates well with the optical bandgap energy. Irrespective of growth conditions, theTiO2 nanostructures exhibit strong near infrared (NIR) photoluminescence (PL) at 1.43?eV and a weak visible PL, which are attributed to the Ti interstitials and O vacancies, respectively, in rutile TiO2 nanostructures. Further, ESR study reveals the presence of singly ionized oxygen vacancy defects. It is observed that lattice distortion depends systematically on the relative concentration and type of defects such as oxygen vacancies and Ti interstitials. XPS analyses revealed a downshift in energy for both Ti 2p and O 1s core level spectra for various growth conditions, which is believed to arise from the lattice distortions. It is proposed that the Ti4+ interstitial and F+ oxygen vacancy defects are primarily responsible for lattice expansion, whereas the electrostatic attraction between Ti4+ interstitial and O2? interstitial defects causes the lattice contraction in the undoped TiO2 nanostructures. The control of lattice parameters through the intrinsic defects may provide new routes to achieving novel functionalities in advanced materials that can be tailored for future technological applications.
TL;DR: In this paper, the authors presented a simulation study of analog circuit performance parameters for a symmetric double-gate junctionless transistor (DGJLT) using dual-material gate along with high-k spacer dielectric (DMG-SP) on both sides of the gate oxides of the device.
Abstract: In this paper, we present a simulation study of analog circuit performance parameters for a symmetric double-gate junctionless transistor (DGJLT) using dual-material gate along with high- k spacer dielectric (DMG-SP) on both sides of the gate oxides of the device. The characteristics are demonstrated and compared with DMG DGJLT and single-material (conventional) gate (SMG) DGJLT. The DMG DGJLT presents superior transconductance (Gm), early voltage (VEA), and intrinsic gain (GmRO) compared with SMG DGJLT. The values are further improved for DMG-SP DGJLT, because high- k spacer enhances the fringing electric fields through the spacer.
TL;DR: An aggregation-induced emission (AIE) active probe (L) displayed TURN-ON fluorescence response toward Al(3+) under physiological conditions and in HeLa cells, which could subsequently facilitate tracking of interaction with DNA in solution.
TL;DR: The metal oxide nanoparticles viz.
Abstract: The effectiveness of the metal oxide nanoparticles viz. CuO and Fe2O3 as antibacterial agents against multidrug resistant biofilm forming bacteria was evaluated. CuO nanoparticles were also experimented for antibiofilm and time kill assay. The CuO displayed maximum antibacterial activity with zone of inhibition of (22 ± 1) mm against methicillin resistant Staphylococcus aureus (MRSA) followed by Escherichia coli (18 ± 1) mm. The Fe2O3 showed the zone of inhibition against MRSA of (14 ± 1) mm followed by E. coli (12 ± 1) mm. CuO proved to be more toxic than Fe2O3 nanoparticles showing significantly high antibacterial activity and found to possess dose dependent antibiofilm properties.
TL;DR: In this article, the structural, optical and ferromagnetic properties of undoped and Fe-doped nanoribbons (NRbs) grown by a solvothermal method were investigated.
Abstract: We have investigated the structural, optical and ferromagnetic properties of undoped and Fe-doped TiO2 nanoribbons (NRbs) grown by a solvothermal method. A strong room temperature ferromagnetism (RTFM) is observed in both undoped and Fe-doped TiO2 NRbs. Fe-doped TiO2 NRbs exhibited a ∼4.8-fold enhancement in RTFM as compared to the undoped NRbs grown under similar conditions. However, the RTFM decreases at higher Fe concentration, possibly due to antiferromagnetic ordering between nearby Fe 3+ ions caused by a super exchange interaction. X-ray diffraction patterns reveal the pure TiO2(B) phase, the TiO2(B)–anatase mixed phase and the anatase–rutile mixed phase of the TiO2 structure. Field emission scanning electron microscopy and transmission electron microscopy observations reveal NRbs with uniform pore distribution and nanopits formed on the surface for both undoped and Fe-doped NRbs. These samples exhibit strong visible photoluminescence associated with oxygen vacancies and the ferromagnetic hysteresis loop, both of which are strongly enhanced after vacuum annealing. Optical absorption, electron spin resonance and x-ray photoelectron spectroscopic analyses are performed to elucidate the origin of RTFM. The observed RTFM in undoped and Fe-doped TiO2 NRbs is qualitatively explained through a model involving bound magnetic polarons, which include an electron locally trapped by an oxygen vacancy with the trapped electron occupying an orbital overlapping with the unpaired electron (3d 1 ) of aT i 3+ ion and/or the unpaired electron (3d 5 ) of aF e 3+ ion. The development of TiO2 NRbs with tunable optical and magnetic properties constitutes an important step towards realizing improved magneto-optical and spintronic devices from novel TiO2 nanostructures.
TL;DR: A prospective review of wavelet-based ECG compression methods and their performances based upon findings obtained from various experiments conducted using both clean and noisy ECG signals is presented.
TL;DR: A fluorescence quenching based non-enzymatic method for sensitive and reliable detection of free bilirubin in blood serum samples using human serum albumin ( HSA) stabilized gold nanoclusters (HSA-AuNCs) as fluorescent probe.
TL;DR: In this article, a comprehensive experimental investigation is presented wherein corrosion performance of steel reinforcement in concrete exposed to composite solutions of chloride and sulfate ions has been evaluated, in which concrete specimens with a centrally embedded steel bar have been prepared from two types of cement namely ordinary Portland cement (OPC) and Portland pozzolana cement (PPC), four w/c ratios and one type of reinforced concrete.
TL;DR: It is shown here that iron( IV)-tosylimido complex is much more reactive with sulfides than the corresponding iron(IV)-oxo complex; however, the reverse trend is obtained for hydrogen atom abstraction reactions.
Abstract: Nature often utilizes molecular oxygen for oxidation reactions through monoxygenases and dioxygenases. In many of these systems, a high-valent iron(IV)-oxo active species is found. In recent years, evidence has accumulated of possible iron(IV)-imido and iron(V)-nitrido intermediates in enzymatic catalysis, although little is known about their activity. In this work, we report a detailed combined kinetics and computational study on the difference in reactivity and chemical properties of nonheme iron(IV)-oxo compared with iron(IV)-tosylimido. We show here that iron(IV)-tosylimido complex is much more reactive with sulfides than the corresponding iron(IV)-oxo complex; however, the reverse trend is obtained for hydrogen atom abstraction reactions. The latter proceed with a relatively small kinetic isotope effect of kH/kD = 7 for the iron(IV)-tosylimido complex. Moreover, a Hammett analysis of hydrogen atom abstraction from para-X-benzyl alcohol reveals a slope of close to zero for the iron(IV)-oxo, whereas a ...
TL;DR: In this paper, an electric circuit-based battery and a capacity fade model suitable for electric vehicles (EVs) in vehicle-to-grid applications were presented, where the circuit parameters of the battery model (BM) were extracted using genetic algorithm-based optimization method.
Abstract: This paper presents an electric circuit-based battery and a capacity fade model suitable for electric vehicles (EVs) in vehicle-to-grid applications. The circuit parameters of the battery model (BM) are extracted using genetic algorithm-based optimization method. A control algorithm has been developed for the battery, which calculates the processed energy, charge or discharge rate, and state of charge limits of the battery in order to satisfy the future requirements of EVs. A complete capacity fade analysis has been carried out to quantify the capacity loss with respect to processed energy and cycling. The BM is tested by simulation and its characteristics such as charge and discharge voltage, available and stored energy, battery power, and its capacity loss are extracted. The propriety of the proposed model is validated by superimposing the results with four typical manufacturers’ data. The battery profiles of different manufacturers’ like EIG, Sony, Panasonic, and Sanyo have been taken and their characteristics are compared with proposed models. The obtained battery characteristics are in close agreement with the measured (manufacturers’ catalogue) characteristics.
TL;DR: A benzothiazole functionalized chemosensor L 1, exhibited colorimetric as well as fluorometric response to Zn 2+ ion at physiological pH based on CHEF process as discussed by the authors.
Abstract: A benzothiazole functionalized chemosensor L 1 , exhibited colorimetric as well as fluorometric response to Zn 2+ ion at physiological pH based on CHEF process. Selective naked eye detection of Zn 2+ ion over most of the biologically important cations was also demonstrated. Sensing of biologically hazardous cadmium ion was also possible with L 1 . Further, both the zinc and cadmium ensembles of L 1 were found to respond P 4 O 7 4− and H 2 PO 4 − anion among other important biological anions and nucleotides via fluorescence quenching. Chemosensor L 1 , was also found to be reversible and recyclable toward Zn 2+ and pyrophosphate ions over more than six cycles and responds to a INHIBIT logic gate. NMR titration and theoretical calculations were also conducted to understand the sensing behavior of L 1 .
TL;DR: Investigation of the effect of iron (Fe) supplementation on arsenic (As) induced oxidative stress responses in rice shows that Fe regulates oxidative stress and promotes growth under As stress.