Indian Institute of Technology Palakkad&nbsp;(IIT Palakkad or IIT PKD) is a public autonomous&nbsp;engineering&nbsp;and&nbsp;research&nbsp;institute located in&nbsp;Palakkad,&nbsp;Kerala. It was&nbsp;one of the five new&nbsp;IITs&nbsp;proposed in the&nbsp;2014 Union budget of India. The campus was inaugurated on 3 August 2015. The institute has 94 faculty, 978 students, and 63 non-teaching staffs.

IT Palakkad currently offers four-year Bachelor of Technology (B.Tech) and two years MS programmes in 8 different engineering disciplines including&nbsp;Computer Science, Electrical, Mechanical, Civil among others.

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IIT Palakkad

We study the effect of coupling magnetic impurities to the honeycomb lattice spin-1/2 Kitaev model in its spin-liquid phase. We show that a spin-S impurity coupled to the Kitaev model is associated with an unusual Kondo effect with an intermediate coupling unstable fixed point Kc∼J/S separating topologically distinct sectors of the Kitaev model. We also show that the massless spinons in the spin-liquid mediate an interaction of the form Siα2Sjβ2/Rij3 between distant impurities unlike the usual dipolar RKKY interaction SiαSjα/Rij3 noted in various 2D impurity problems with a pseudogapped density of states of the spin bath. Furthermore, this long-range interaction is possible only if the impurities (a) couple to more than one neighboring spin on the host lattice and (b) the impurity spin S≠ 1/2. © 2010 The American Physical Society.

Department of Physics

World University root node

Fulltext

Physical Review Letters

Magnetic impurities in the honeycomb Kitaev model

Planning methods such as CPM and PERT cannot model the iterative details of design processes. It has been demonstrated that the Dependency Structure Matrix (DSM) is an effective method to model iterative process. However, formulating the DSM on large construction projects, using current methodologies is challenging. To address this challenge, a structured methodology called Design Interface Management System "diMs" has been proposed. As the documents and interactions required for implementing the "diMs" process are voluminous, support of an IT based tool is essential. This paper presents the design and the development of the tool. It includes the design of class structure, relational database and communication engine using object oriented concepts. In addition, the design of user interface which consists of a set of dynamic web pages is also explained. The paper also illustrates the usage of the tool for the design of a glass factory and discusses the utility of the tool in assisting design interface management. {\textcopyright} 2009 Elsevier B.V. All rights reserved.

Department of Civil Engineering

Automation in Construction

A web-based system for design interface management of construction projects

Environmental Sciences and Sustainable Engineering Centre (ESSENCE)

The Pennsylvania State University

Soil phosphorus dynamics in a sprinkler irrigation system for land application of municipal wastewater effluent

The dynamics and diagnostics of cracked rotors have been gaining importance in recent years. The present work deals with the detection of crack in rotor system and determination of crack parameters i.e., position of crack, depth of crack using Artificial Neural Networks (ANN). The detection of crack is based on the Continuous Wavelet Transform (CWT) plots with 1/3 and 1/2 critical peaks as the crack indicators. The input to the CWT is the transient data which is obtained from the cracked run-up rotor with stepped acceleration, which is encountered in real time situations during the operation of steam turbines, aero-engines etc. The amplitudes of sub-critical and critical peaks of the CWT plots are fed as input to the neural network to obtain the crack parameters. The new concept in the present work is that both qualitative and quantitative treatment has been applied to diagnose the system and by using a simple data modification technique the number of sensors have been deduced from 21 to 3 for a 20 element FEM rotor model. © KRISHTEL eMAGING SOLUTIONS PRIVATE LIMITED.

Department of Mechanical Engineering

Advances in Vibration Engineering

Shaft crack identification using artificial neural networks and wavelet transform data of a transient rotor

Let A be a complex commutative Banach algebra with unit 1 and δ &gt; 0. A linear map φ: A →C is said to be δ-almost multiplicative if |φ(ab) - φ (a) φ (b)| ≤ δ||a|| ||b|| for all a, b ε A. Let 0 &lt; e &lt; 1. The e-condition spectrum of an element a in A is defined by δe.(a) := {λ ε C:||λ-a||||λ- a||-1 ||≥ 1/e} with the convention that ||λ- a|| ||(λ - a)-1|| = ∞ when λ - a is not invertible. We prove the following results connecting these two notions: (1) If φ(1) = 1 and φ is δ-almost multiplicative, then φ(a) ε δe(a) for all a in A.then (2) If φis lenear and φ(a) εδe(a) for all a in A ,then φ-is δ almost multiplicative for some δ. The first result is analogous to the Gelfand theory and the last result is analogous to the classical Gleason-Kahane- Żelazko theorem.

Department of Mathematics

Studia Mathematica

Almost multiplicative functions on commutative Banach algebras

Problem statement: Conventional Proportional-Integral-Derivative (PID) controllers exhibit moderately good performance once the PID gains are properly tuned. However, when the dynamic characteristics of the system are time dependent or the operating conditions of the system vary, it is necessary to retune the gains to obtain desired performance. This situation has renewed the interest of researchers and practitioners in PID control. Self-tuning of PID controllers has emerged as a new and active area of research with the advent and easy availability of algorithms and computers. This study discusses self-tuning (auto-tuning) algorithm for control of autonomous underwater vehicles. Approach: Self-tuning mechanism will avoid time consuming manual tuning of controllers and promises better results by providing optimal PID controller settings as the system dynamics or operating points change. Most of the self-tuning methods available in the literature were based on frequency response characteristics and search methods. In this study, we proposed a method based on Taguchi's robust design method for self-tuning of an autonomous underwater vehicle controller. The algorithm, based on this method, tuned the controller gains optimally and robustly in real time with less computation effort by using desired and actual state variables. It can be used for the Single-Input Single-Output (SISO) systems as well as Multi-Input Multi-Output (MIMO) systems without mathematical models of plants. Results: A simulation study of the AUV control on the horizontal plane (yaw plane control) was used to demonstrate and validate the performance and effectiveness of the proposed scheme. Simulation results of the proposed self-tuning scheme are compared with the conventional PID controllers which are tuned by Ziegler-Nichols (ZN) and Taguchi's tuning methods. These results showed that the Integral Square Error (ISE) is significantly reduced from the conventional controllers. The robustness of this proposed self-tuning method was verified and results are presented through numerical simulations using an experimental underwater vehicle model under different working conditions. Conclusion/Recommendations: By using this scheme, the PID controller gains are optimally adjusted automatically online with respect to the system dynamics or operating condition changes. This technique found to be more effective than conventional tuning methods and it is even very convenient when mathematical models of plants are not available. Computer simulations showed that the proposed method has very good tracking performance and robustness even in the presence of disturbances. The simple structure, robustness and ease of computation of the proposed method make it very attractive for real time implementation for controlling of underwater vehicle and it offers a chance to extend the same technique to the three dimensional vehicle tracking control as well. © 2010 Science Publications.

Journal of Computer Science

A self-tuning proportional-integral-derivative controller for an autonomous underwater vehicle, Based on Taguchi method

Modern rotating machinery is prone to fatigue cracks due to the severe working and continuously varying loading conditions. To avoid failure of the rotating systems due to these cracks, the system needs to be continuously monitored. The reliability of the machinery can be enhanced with the fault identification at the early stages of their occurrence. Model based methods are used for crack identification in rotating systems successfully. Model based methods are of different types. One of the methods, the equivalent loads minimization method is studied here. It has a limitation that the error in identified crack depth increases with decrease in number of measured vibrations. In the present work, the theoretical fault model loads used in least squares minimization algorithm are transformed using modal expansion to reduce error in the identified fault parameters. The crack is identified accurately even in the case of less number of measured vibrations. The method is applied for crack identification in a centrifugal pump rotor using transverse vibrations. The results presented are obtained purely from FEM simulations. Copyright © 2010 by ASME.

Proceedings of the ASME Turbo Expo

Model based shaft crack identification in rotating machinery

In this paper, we consider the problem of scheduling in multihop wireless networks subject to interference constraints. We consider a graph based representation of wireless networks, where scheduled links adhere to the K-hop link interference model. We develop a distributed greedy heuristic for this scheduling problem. Further, we show that this distributed greedy heuristic computes the exact same schedule as the centralized greedy heuristic. ©2010 IEEE.

Department of Computer Science and Engineering

2010 IEEE 7th International Conference on Mobile Adhoc and Sensor Systems, MASS 2010

Distributed greedy scheduling for multihop wireless networks

The bacterium Escherichia coli (E. coli) moves in its natural environment in a series of straight runs, interrupted by tumbles which cause change of direction. It performs chemotaxis towards chemo-attractants by extending the duration of runs in the direction of the source. When there is a spatial gradient in the attractant concentration, this bias produces a drift velocity directed towards its source, whereas in a uniform concentration, E. coli adapts, almost perfectly in case of methyl aspartate. Recently, microfluidic experiments have measured the drift velocity of E. coli in precisely controlled attractant gradients, but no general theoretical expression for the same exists. With this motivation, we study an analytically soluble model here, based on the Barkai-Leibler model, originally introduced to explain the perfect adaptation. Rigorous mathematical expressions are obtained for the chemotactic response function and the drift velocity in the limit of weak gradients and under the assumption of completely random tumbles. The theoretical predictions compare favorably with experimental results, especially at high concentrations. We further show that the signal transduction network weakens the dependence of the drift on concentration, thus enhancing the range of sensitivity. © 2010 Elsevier Ltd.

Journal of Theoretical Biology

Theoretical results for chemotactic response and drift of E. coli in a weak attractant gradient

A methodology is developed for the analysis of diesel engine in-cylinder processes and combustion. Beginning from CAD data of the engine geometry, the methodology involves use of a commercial code AVL FIRE for simulation of suction stroke and an open-source code KIVA-3V for simulation of the closed-valve part of the diesel cycle. For this, an algorithm is first developed to map a generalised three-dimensional Computational Fluid Dynamics (CFD) solution from an unstructured mesh in AVL FIRE to a structured mesh in KIVA-3V to provide initial conditions for the closed-valve simulations. For simulation of diesel combustion process, an integrated KIVA-3V code is developed by incorporating two well-validated models into the standard code: the Shell hydrocarbon auto-ignition model for simulation of diesel auto-ignition under conditions of high temperature and pressure and the Characteristic-time model for simulation of subsequent diesel combustion. The integrated code is validated and calibrated against experimental pressure measurements in a naturally aspirated direct injection diesel engine. These tools are then used for exploring the potential of a constant-speed, turbocharged diesel engine towards emission reduction. The case study involves combustion simulations for exploring multiple injection strategy for the engine concerned. Copyright © 2010 Inderscience Enterprises Ltd.