Showing papers by "Indian Institute of Technology Bhubaneswar published in 2010"
TL;DR: In this paper, a performance-based plastic design (PBPD) methodology for the design of buckling-restrained braced frames (BRBFs) is presented, where the design base shear is obtained based on energy-work balance using pre-selected target drift and yield mechanism.
146 citations
TL;DR: Four different arene and heteroarene series have been subjected to local nucleophilicity analysis in order to predict the site selectivity in electrophilic aromatic substitution reactions (EAS) with excellent correlation with the experimental result.
Abstract: By using the inverse concept of electrophilicity and nucleophilicity and with four different available equations from literature for electrophilicity and electrodonating power, the nucleophilicity values of 69 commonly used arenes and heteroarenes have been calculated at the B3LYP/6-311+G(d,p) level of theory. The linearity between the nucleophilicity and Hammett sigma and sigma(p) values has been chosen as a test to judge the goodness of the methods used. Finally four different arene and heteroarene series (substituted indoles, phenols, pyrroles, and anisoles) have been subjected to local nucleophilicity analysis in order to predict the site selectivity in electrophilic aromatic substitution reactions (EAS). In each case we have obtained excellent correlation with the experimental result.
94 citations
TL;DR: In this paper, the authors presented the response of piles in liquefiable soil under seismic loads and the effects of soil, pile, and earthquake parameters on the two potential pile failure mechanisms, bending and buckling, are examined.
Abstract: This paper presents the response of piles in liquefiable soil under seismic loads. The effects of soil, pile, and earthquake parameters on the two potential pile failure mechanisms, bending and buckling, are examined. The analysis is conducted using a two-dimensional plain strain finite difference program considering a nonlinear constitutive model for soil liquefaction, strength reduction, and pile-soil interaction. The depths of liquefaction, maximum lateral displacement, and maximum pile bending moment are obtained for concrete and steel piles for different soil relative densities, pile diameters, earthquake predominant frequencies, and peak accelerations. The potential failure mechanisms of piles identified from the parametric analysis are discussed.
62 citations
TL;DR: A nucleophilic substitution of propargylic alcohols with carbon, heteroarene, and allyltrimethylsilane, sulfur, oxygen, and nitrogen nucleophiles has been demonstrated using a high-valent catalyst in 1,2-dichloroethane to afford the corresponding prop argylic products in moderate to excellent yields.
Abstract: A nucleophilic substitution of propargylic alcohols with carbon (arene, heteroarene, and allyltrimethylsilane), sulfur (thiol), oxygen (alcohol), and nitrogen (sulfonamide) nucleophiles has been demonstrated using a high-valent [Ir(COD)(SnCl(3))Cl(mu-Cl)](2) catalyst in 1,2-dichloroethane to afford the corresponding propargylic products in moderate to excellent yields. Alkyl or aryl substituted tertiary propargylic alcohols produce substituted indenes with bulky arenes via allenylic intermediate. An electrophilic mechanism is proposed from Hammett correlation.
55 citations
TL;DR: In this paper, a seismic strengthening technique using aluminum shear links as energy-dissipating devices to enhance the lateral strength, stiffness, and energy dissipation potential of the existing reinforced concrete (RC) frames is presented.
52 citations
TL;DR: By combining the principles of AIS and PSO, two new but simple hybrid algorithms called Clonal PSO (CPSO) and ImmunizedPSO (IPSO) are proposed which involve less complexity and offers better identification performance.
Abstract: Identification of Hammerstein plants finds extensive applications in stability analysis and control design. For identification of such complex plants, the recent trend of research is to employ nonlinear network and to train their weights by evolutionary computing tools. In recent years the area of Artificial Immune System (AIS) has drawn attention of many researchers due to its broad applicability to different fields. In this paper by combining the principles of AIS and PSO, we propose two new but simple hybrid algorithms called Clonal PSO (CPSO) and Immunized PSO (IPSO) which involve less complexity and offers better identification performance. Identification of few benchmark Hammerstein models is carried out through simulation study and the results obtained are compared with those obtained by standard PSO, Clonal and GA based methods. Various simulation results demonstrate that IPSO algorithm offers best identification performance compared to the other algorithms. Out of the two algorithms proposed, the CPSO is computationally simpler but offers identification performance nearly similar to its PSO counterpart.
50 citations
TL;DR: The results show that completely embedded fibers do not degrade over a long time, while partially embedded fibers can preserve the large evanescent waves without undergoing considerable degradation, which would be further reduced or even become negligible with functional overlayers.
Abstract: We present a technique to embed silica micro and nanofibers in low-index material (Teflon) using an inexpensive and straightforward fabrication process based on spin coating. The optical properties of the silica micro/nano-fibers have been investigated when they are bare or completely or partially embedded. Optical degradation occurs in bare fibers with diameters smaller than twice the wavelength of the guided light, thus making protection through embedding necessary. Our results also show that completely embedded fibers do not degrade over a long time, while partially embedded fibers can preserve the large evanescent waves without undergoing considerable degradation, which would be further reduced or even become negligible with functional overlayers. The results represent a step forward toward the development of durable and stable devices based on optical micro/nano fibers.
39 citations
TL;DR: In this article, both elasto-plastic and degrading hysteresis behavior for lateral load-resisting structural elements are considered for low-rise buildings with stiff periods.
Abstract: Relying on the ductile behaviour of structures during earthquake, building codes introduce response reduction factors ( R ) to reduce design forces in earthquake resistant design. However, applicability of such factors has not been systematically explored for low-rise buildings with stiff periods. Present study is an attempt to address this issue. Both elasto-plastic and degrading hysteresis behaviour for lateral load-resisting structural elements are considered herein, while sub-soil is idealized as linear and elasto-plastic in parallel. The study recognizes that inelastic response for short period systems is very sensitive to R and may be phenomenally amplified even for small R due to soil–structure interaction implying restrictive applicability of dual-design philosophy. Limited study on the plan-asymmetric low-rise buildings depicts that inelastic response of the asymmetric structure relative to its symmetric counterpart is not appreciably influenced due to soil–structure interaction (SSI). The study also confirms that equivalent single story model characterized by the lowest period rather than the fundamental one of the real system tends to yield conservative estimation of inelastic demand at least for the short-period systems.
36 citations
TL;DR: The nature of substrate activation, and initial bond breaking/making steps, and the dependence of initial rate (k) with diene ligand is in the order COD > NBD > CHD; which corresponds well with the order of hardness of the respective Ag(I) complexes.
Abstract: Silver(I) complex [Ag(diene)2]+Y− (where diene = cyclooctadiene, norbornadiene, and 1,3-cyclohexadiene; Y− = PF6−, BF4−) efficiently catalyzes the arylation of N-tosylaziridines with arenes and heteroarenes under ambient condition to provide the corresponding β-aryl amine derivatives with excellent regioselectivity. To understand the nature of substrate activation, and initial bond breaking/making steps, the following studies were conducted with the help of in situ NMR (1H, 31P, 109Ag) and ESI-MS probe: (I) evaluation of Hammett reaction constant (ρ); (II) correlation of initial rate (k) versus cone angle (θ) of ligand L for reactions mediated by [Ag(COD)2]PF6/L (where L is a phosphine or a phosphite ligand); (III) identification of silver−arene intermediates in solution; and (IV) correlation of initial rate (k) with ΔHOMO−LUMO of [Ag(diene)2]PF6 obtained from preliminary DFT studies. Study I led to a ρ-value of −0.586, indicating that the extent of electrophilic perturbation is considerably less than a t...
29 citations
TL;DR: Improvement in prediction accuracy of model for thermosyphon solar water heating system is focused on by employing grey-box modeling approach based on fuzzy system to predict the outlet water temperature.
25 citations
01 Dec 2010
TL;DR: The work of this project is to study, evaluate and compare the various techniques of the DTC-SVM with three level inverter applied to the induction machines through simulations, which includes dynamic torque and flux responses, feasibility and the complexity of the systems.
Abstract: Direct Torque Control is a control technique used in AC drive systems to obtain high performance torque control. The conventional DTC drive contains a pair of hysteresis comparators, a flux and torque estimator and a voltage vector selection table. The torque and flux are controlled simultaneously by applying suitable voltage vectors, and by limiting these quantities within their hysteresis bands, decoupled control of torque and flux can be achieved. However, as with other hysteresis-bases systems, DTC drives utilizing hysteresis comparators suffer from high torque ripple and variable switching frequency. The most common solution to this problem is to use the space vector with multilevel inverter depends on the reference torque and flux. The reference voltage vector is then realized using a voltage vector modulator. Several variations of DTC-SVM with three level inverter have been proposed and discussed in the literature. The work of this project is to study, evaluate and compare the various techniques of the DTC-SVM with three level inverter applied to the induction machines through simulations. The simulations were carried out using MATLAB/ SIMULINK simulation package. Evaluation was made based on the drive performance, which includes dynamic torque and flux responses, feasibility and the complexity of the systems. It is better technology in electric vehicles.
TL;DR: In this article, the supramolecular assemblies of 4-hydroxyphenylboronic acid with aza-donor compounds demonstrating that the B(OH)2 moiety forms interactions with a zononor compound as much as -OH does.
20 Dec 2010
TL;DR: In this article, the four wave mixing effect of dense wavelength division multiplexing (DWDM) in a Radio-over-Fiber (RoF) system is discussed.
Abstract: In this paper, we have discussed in detail the four wave mixing (FWM) effect of dense wavelength division multiplexing (DWDM) in Radio-over-Fiber (RoF) system. A 32-channel 40-Gbps system is considered. FWM effect for various channel spacing, input power level, effective fiber area and modulation formats are analyzed. Different schemes for minimizing these effects are discussed for the first time. Considering all these effects, an optimized DWDM setup is designed using single parameter optimization (SPO) technique.
TL;DR: In this paper, an improved higher-order zigzag theory for vibration of soft core sandwich plates in random environment is proposed, which exploits all the merits of layer-wise theory, including the effect of core transverse normal strain and simultaneously enjoys the benefits of single layer theory in terms of computational efficiency.
Abstract: An improved higher-order zig-zag theory for vibration of soft core sandwich plates in random environment is proposed. It exploits all the merits of layer-wise theory, includes the effect of core transverse normal strain and simultaneously enjoys the benefits of single layer theory in terms of computational efficiency. The core is modeled as a 3-D elastic continuum. An efficient C 0 finite element is developed for the implementation of the proposed theory. A first order perturbation approach is employed to handle the randomness in the lamina material properties. Second order statistics of natural frequencies are computed and validated with independent Monte Carlo simulation.
TL;DR: In this article, a comparative study has been carried out on tensile properties and failure mechanisms of Al-4·5 wt-%Cu alloy and in situ Al 4·5Cu-5TiB2 composite in as cast or mushy state rolled conditions.
Abstract: A comparative study has been carried out on tensile properties and failure mechanisms of Al–4·5 wt-%Cu alloy and in situ Al–4·5Cu–5TiB2 composite in as cast or mushy state rolled conditions. For the alloy, mushy state rolling at temperature for 30 vol.-% nominal liquid content to 2·5% thickness reduction leads to marginally higher strength but poorer ductility, while both these properties worsen significantly on 5% reduction because of grain growth and intergranular solute segregation. Contrarily, mechanical properties of the composite are significantly improved on mushy state rolling at temperatures for 10–30 vol.-% liquid to 2·5–5% reduction. Improvement in mechanical properties of the composite on mushy state rolling is attributed to evolution of globular and finer grains. Examination of fracture surfaces by scanning electron microscope has shown evidence of ductile failure in as cast alloy and in cast or mushy state rolled composite, but that of brittle failure in mushy state rolled alloy.
26 Nov 2010
TL;DR: The robust norm is introduced in incremental cooperative distributed network to estimate the desired parameters in presence of Gaussian contaminated impulsive noise.
Abstract: Distributed wireless sensor networks have been proposed as a solution to environment sensing, target tracking, data collection and others. Energy efficiency, high estimation accuracy, and fast convergence are important goals in distributed estimation algorithms for WSN. This paper studies the problem of robust adaptive estimation in impulsive noise environment using robust cost function like Wilcox on norm and error saturation nonlinearity. The incremental cooperative scheme conventionally used in sensor network in which each node have local computing ability and share them with their predefined neighbors, is not robust to impulsive type of noise or outliers. In this paper the robust norm is introduced in incremental cooperative distributed network to estimate the desired parameters in presence of Gaussian contaminated impulsive noise.
20 Jun 2010
TL;DR: An investigation has been made on the behavior of Indian consumers towards online shopping using Functional link artificial neural network (FLANN) and the result is compared with that obtained from the conventional statistical based approach, discriminant analysis.
Abstract: The rapid development of internet usage has paved the way towards the use of online shopping. In this paper an investigation has been made on the behavior of Indian consumers towards online shopping using Functional link artificial neural network (FLANN) and the result is compared with that obtained from the conventional statistical based approach, discriminant analysis. The simulation study reveals that the FLANN based model provides improved classification of consumers compared to the conventional statistical based approach.
16 Oct 2010
TL;DR: Sign regressor Wilcoxon and sign-sign wilcoxon as mentioned in this paper are robust against the outlier present in the desired data and also faster than Wilcox and sign Wilcoxton norm, which is known that sign LMS and sign regressor LMS are faster than LMS.
Abstract: It is known that sign LMS and sign regressor LMS are faster than LMS. Inspiring from this idea we have proposed sign regressor Wilcoxon and sign-sign wilcoxon which are robust against the outlier present in the desired data and also faster than Wilcoxon and sign Wilcoxon norm. It had applied to varities of linear and nonlinear system identification problems with Gaussian noise and impulse noise present in the desired. The simulation results are compared among Wilcoxon, sign Wilcoxon and proposed sign-sign Wilcoxon and sign-regressor Wilcoxon. From simulation results it has proved that the proposed techniques are robust against outlier in the desired data
TL;DR: This is a novel attempt to capture psychosis data by considering 24 input symptom constructs and 7 tentative responses (outputs) as per Brief Psychiatric Rating Scale-F2 as per Plackett-Burman design (PBD).
TL;DR: The objective is to find the applicability of soft computing techniques, swarm-intelligence based neural network, and adaptive fuzzy models in the prediction of boiling HTC in terms of root mean square of prediction error.
Abstract: In this article pool boiling heat transfer coefficient (HTC) of liquids (isopropanol, methanol, and distilled water) on copper-coated heating tubes over a wide range of pressure conditions is computed experimentally. The objective is to find the applicability of soft computing techniques, swarm-intelligence based neural network, and adaptive fuzzy models in the prediction of boiling HTC. The results are compared with those computed experimentally. The performance of models for prediction of HTC is analyzed in terms of root mean square of prediction error. The minimum/maximum value obtained by zero-order fuzzy model with six membership function is 0.0023/3.4383 among all the liquids considered. The model is found to predict HTC with a maximum error of ±0.5% for boiling of liquids over all the coated tubes with pressure varying from atmospheric to subatmospheric levels. The study shows an excellent agreement between the experimental and predicted data.
16 Sep 2010
TL;DR: Novel techniques for placement based on constricted particle swarm optimization (PSO), adaptive PSO and time varying inertia weight (TVIW) PSO are proposed and the results of simulation reveal a competitive performance of the circuits implemented.
Abstract: Field programmable gate array (FPGA) is a widely used programmable integrated circuit (IC) for fast realization of digital circuits in all electronic systems. Its reconfigurability has made this mode of digital circuit synthesis more popular among the system designers. But unlike other ICs it provides a restricted hardware structure for circuit implementation and hence the computer aided design (CAD) software is also constrained. The placement being a very vital step in the design process needs to be performed optimally for high performance circuits. In these work novel techniques for placement based on constricted particle swarm optimization (PSO), adaptive PSO and time varying inertia weight (TVIW) PSO are proposed. The results of simulation reveal a competitive performance of the circuits implemented. The technique proposed here also offer faster convergence to a placement solution. The performance of a single BCD counter circuit is studied in details by using the different PSO algorithms. The netlist generated from the Xilinx design tool is used for placement and optimization results are reported here.
01 Oct 2010
TL;DR: This paper investigates a general class of distributed algorithms for data processing, eliminating the need to transmit raw data to a central processor and finding one that can provide significant reductions in the amount of communication and energy required to obtain an accurate estimate.
Abstract: Wireless sensor networks (WSN) have been proposed as a solution to environment sensing, target tracking, data collection and others. WSN collect an enormous amount of data over space and time. The objective is to estimate of a parameter or function from these data. Learning is used in detection and estimation problems when no probablistic model relating an observation. This paper investigates a general class of distributed algorithms for data processing, eliminating the need to transmit raw data to a central processor. This can provide significant reductions in the amount of communication and energy required to obtain an accurate estimate. The estimation problems we consider are expressed as the optimization of a cost function involving data from all sensor nodes. Here the distributed algorithm is based on an incremental optimization process. A parameter estimate is circulated through the network, and along the way each node makes a small adjustment to the estimate based on its local data.
18 Nov 2010
TL;DR: Novel techniques for placement based on simple particle swarm optimization (PSO), constricted PSO and time varying inertia weight (TVIW) PSO are proposed taking bounding box cost into consideration and reveal a competitive performance of the circuits implemented.
Abstract: Digital ICs for electronic systems are fast realized on Field programmable gate array (FPGA). The reconfigurability of FPGA has made this mode of digital circuit synthesis more popular among the system designers. But unlike other ICs it provides a restricted hardware structure for circuit implementation and hence the computer aided design (CAD) software is also constrained. The placement being a very vital step in the design process needs to be performed optimally for high performance circuits. In this work novel techniques for placement based on simple particle swarm optimization (PSO), constricted PSO and time varying inertia weight (TVIW) PSO are proposed taking bounding box cost into consideration. The results of simulation reveal a competitive performance of the circuits implemented. The technique proposed here also offer faster convergence to a placement solution. The performance of a single BCD counter circuit is studied in details by using the different PSO algorithms. The netlist generated from the Xilinx design tool is used for placement and optimization results are reported here.
TL;DR: In this paper, the authors reviewed the current available literatures concerning N2O emissions from wastewater treatment facilities, biosolids landfilling, and composting, and concluded that each process can release a...
Abstract: All degradable organic materials are decomposed by microorganisms, and considerable amounts of nitrogen end up as gaseous metabolites. No matter what procedure is chosen for getting rid of organic wastes (wastewater treatment, landfiling, and composting), microbial communities will always be involved in the decomposition process, and hence, emissions of greenhouse gases, including nitrous oxide ( N2 O ) , are inevitable with these processes. N2 O is an influential greenhouse gas, vital on climate change, and also is a depleting substance of stratospheric ozone. Any instantaneous or eventual N2 O emissions during wastewater treatment, biosolids landfilling, and composting must be measured as anthropogenic intrusion of global N2 O cycle, and thus plays a decisive role in ozone depletion. This paper reviews the current available literatures concerning N2 O emissions from wastewater treatment facilities, biosolids landfilling, and composting. The outcome of this survey portrays that each process can release a...
26 Nov 2010
TL;DR: This work considers the problem of information discovery in a densely deployed wireless Sensor Network (WSN) where the initiator of search is unaware of target information and proves by theoretical analysis that IRS is independent of node density.
Abstract: Since sensor networks can be thought of as a distributed database system, several architectures proposed to interface the application to the sensor network through querying protocol. However sensor networks are so massively distributed, so careful consideration should be put into the efficient organization of data and the execution of queries. Here we consider the problem of information discovery in a densely deployed wireless Sensor Network (WSN) where the initiator of search is unaware of target information. A new type of protocol based on Increasing Ray Search (IRS) which is an energy efficient and scalable search protocol is discussed. The basic principle of this protocol is to route the search packet along a set of trajectories called rays that maximizes the likelihood of discovering of the target information by consuming least number of transmission. The rays are organized such that if the search packet travels along all these rays, then the entire terrain area will be covered by its transmissions. We compare IRS with existing query resolution techniques for unknown target location such as, Expanding Ring Search, Random Walk Search, and Gossip Search. We prove by theoretical analysis that IRS is independent of node density.
TL;DR: In this article, the impact of forest protection committees (FPCs) under JFM on stress migration in four forest divisions of Orissa has been examined by adopting a logit regression model at household level.
Abstract: In this study, an attempt has been made to unravel the impact of forest protection committees (FPCs) under JFM on stress migration in four forest divisions of Orissa. In order to undertake this study, field investigations have been carried out in 12 villages of four forest divisions of the state. Our study has covered 318 households comprising of landless and agriculture labourer, marginal, small, and medium farmers from 12 different villages where FPCs are operating since early 1990s. The household level benefits have been estimated in terms of employment generation, income from timber and non-timber forest products (NTFP), and fuel wood collection from community managed forests. Further, we have examined the impact of JFM via FPCs on environmental stress migration (ESM) by adopting a Logit Regression Model at household level. It has been found that the employment opportunities have increased significantly since the establishment of FPCs. The findings of the study establish that the improvement in forest...
TL;DR: The results demonstrate that MOPSO outperforms the existing two methods for the considered test cases and simultaneously maximise the return and minimise the associated risk.
Abstract: Efficient portfolio design is a real challenge in the area of computational finance. Optimisation based on Markowitz (1959) two-objective mean-variance approach is computationally expensive for real financial world. Practical portfolio design introduces further complexity as it requires the optimisation of multiple return and risk measures. Some of these measures are non-linear and non-convex. Three well known multi-objective evolutionary algorithms, i.e., Pareto envelope-based selection algorithm, micro-genetic algorithm and multi-objective particle swarm optimisation are chosen and applied for solving the bi-objective portfolio optimisation problem which simultaneously maximise the return and minimise the associated risk. Performance comparison is obtained by carrying out using practical data. The results demonstrate that MOPSO outperforms the existing two methods for the considered test cases.
TL;DR: PF6 catalyzes the reaction between propargyl alcohols and N-tosylaziridines/azetidines leading to a diverse range of N,O-heterocycles, namely, oxazines, oxazepines, and oxazocines via ring opening and ring closing in a cascade as discussed by the authors.
Abstract: [Ag(COD)2]PF6 catalyzes the reaction between propargyl alcohols and N-tosylaziridines/azetidines leading to a diverse range of N,O-heterocycles, namely, oxazines, oxazepines, and oxazocines via ring-opening and ring-closing in a cascade
TL;DR: In this article, the authors presented an attempt to capture inelastic seismic response incorporating P-Δ effect for single degree of freedom (SDOF) and multiple degrees of freedom systems with representative short period, medium period and long period structures.
Abstract: Structures are designed to dissipate input seismic energy by performing hysteresis cycles through repetitive inelastic excursions. P–Δ effect becomes prominent during inelastic seismic excursions and may considerably increase the ductility demand. Furthermore, ductility demand, prima facie, is regulated by lateral strength and hysteresis behaviour of structural material. In this context, this paper presents an attempt to capture inelastic seismic response incorporating P–Δ effect for single degree of freedom (SDOF) and multiple degrees of freedom (MDOF) systems with representative short period, medium period and long period structures. Four hysteresis behaviours, namely: (a) elasto-plastic, (b) only stiffness degrading, (c) only strength deteriorating and (d) both strength and stiffness degrading hysteresis behaviours are considered to cover all possible material characteristics. Rigorous nonlinear dynamic analysis is performed and the ratios of displacement ductility demands and overturning moments obtai...