Showing papers by "PSG College of Technology published in 2004"

Photophysical properties of coumarin-30 dye in aprotic and protic solvents of varying polarities

Abstract: Experimental results on various photophysical properties of coumarin-30 (C30) dye, namely, Stokes' shift (Δν), fluorescence quantum yield (Φf), fluorescence lifetime (τf), radiative rate constant (kf) and nonradiative rate constant (knr), as obtained using absorption and fluorescence measurements have been reported. Though in most of the solvents the properties of C30 show more or less linear correlation with the solvent polarity function, Δf = {(e − 1)/(2e + 1) − (n2 − 1)/(2n2 + 1)}, they show unusual deviations in nonpolar solvents at one end and in high-polarity protic solvents at the other end. From the solvent polarity and temperature effect on the photophysical properties of the dye, following inferences have been drawn: (1) in nonpolar solvents, the dye exists in a nonpolar structure, where its 7-NEt2 substituent adopts a pyramidal configuration and the amino lone pair is out of resonance with the benzopyrone π cloud; (2) in medium to higher polarity solvents, the dye exists in a polar int...

Evaluation of antioxidant properties of berries

Abstract: The present paper focuses on assessing the levels of various enzymatic and non-enzymatic antioxidants in selected berries of Indian sub-continent viz., gooseberry, grapes, orange and tomato. This study has revealed that orange, tomato and grapes possess predominant quantities of enzymatic antioxidants namely SOD, catalase and glutathione peroxidase respectively. The levels of antioxidants analyzed namely reduced glutathione, vitamin C and vitamin A were maximal in grapes, orange and tomato respectively. All the extracts of berries included in the present study inhibited iron inducedin vitro lipid peroxidation in erythrocytes, the extend of inhibition being highest for gooseberry and orange compared to tomato and grapes which could be attributed to their in-built antioxidant system.

QFD‐ and VE‐enabled target costing: a fuzzy approach

Abstract: Globalization has provided excellent opportunities for the global manufacturing community together with a stringent barrier on cost control. Target costing has emerged as one of the main tools in aiding the manufacturers to be globally competitive. This paper analyses the effect of tools such as quality function deployment (QFD) and value engineering (VE) on target costing and explores the way in which these tools assist in achieving the target cost. The target costing model developed by Cooper and Slagmulder (Cooper, R. and Slagmulder, R., Target Costing and Value Engineering, Productivity Press, New York, NY, 1997) has been modified and tools such as QFD and VE have been incorporated in the model. Due to inherent uncertainties in the associated cost of various elements, the model has been further strengthened with the use of fuzzy logic. The theoretical model developed was implemented in an Indian auto component manufacturing company and the results were analysed. Target costing significantly relies upon QFD and VE for its effective implementation. Uncertainty in cost estimation plays a significant role in the target costing process since any variation in cost violates the cardinal rule of target costing, “the target cost should never be exceeded”. Fuzzy logic plays a vital role in accounting for uncertainty in the target costing process and gives a different perspective to arrive at the function cost. A functional approach (VE) combined with QFD backed by fuzzy approach appears to work effectively for a target costing process that is evidenced from the case study. It appears that the model developed will work satisfactorily for an industrial product and the validity of the model for fast moving consumer goods has to be ascertained.

Functional Networks in Structural Engineering

Abstract: In this paper, functional networks (FN) proposed by Castillo as an alternative to neural networks are discussed. Unlike neural networks, the functions are learned instead of weights. In general, topology is selected based on data, domain knowledge (properties of the function such as associativity, commutativity, and invariance), or a combination of the two. The object of this paper is to show the application of some functional network architectures to model and predict the behavior of structural systems which are otherwise modeled in terms of differential or difference equations or in terms of neural networks. In this paper, four examples in structural engineering and one example in mathematics are discussed. The results obtained by functional networks are compared with those obtained by neural networks for the first four examples, and it is shown that functional networks are more efficient and powerful and take much less computer time as compared to predictions by conventional neural networks such as the back-propagation network.

Aldimines - effective corrosion inhibitors for mild steel in hydrochloric acid solution

Abstract: New and effective aldimine types of corrosion inhibitors namely, N-methylidene octylamine (MOA), N-ethylidene octylamine (EOA) and N-propylidene octylamine (POA) have been synthesized. Their inhibition efficiency was investigated for the corrosion of mild steel in 1 M HCl solution by various corrosion monitoring techniques. A preliminary screening of the inhibition efficiency of the inhibitors was carried out by weight loss and gasometric studies. They were found to behave as good inhibitors in 1 M HCl solution. Potentiodynamic polarization measurements show that aldimines are mixed type inhibitors. The extent of the decrease in the hydrogen permeation current through the mild steel surface was studied by the hydrogen permeation technique and it was found that the decrease was in the order POA > EOA > MOA. Double layer capacitance and charge transfer resistance values were derived from Nyquist plots obtained from AC impedance studies. The adsorption of these compounds on mild steel from 1 M HCl solution obeys the Temkin adsorption isotherm.

The optimisation of space structures using evolution strategies with functional networks

Abstract: In this work, the input for large space structures is created using the Formex algebra of the Formian software. The different search and optimisation algorithm known as evolution strategies (ESs) has been applied to find the optimal design of the space trusses considering the areas of the members of the space structures as discrete variables. The objective function is obtained for first few generations by using a structural analysis package such as Feast and for other generations by functional networks (FNs). Initially, to obtain the data for a functional network, a structural package such as Feast is used. The use of a functional network is motivated by time consuming repeated analyses required by evolution strategies during the optimisation process. In addition, a multilevel optimisation approach is implemented by reducing the size of the search space for individual design variables in each successive level of the optimisation process for the first example; for the remaining three examples, a functional network has been combined with evolution strategies to get away with the use of a structural analysis package and a multilevel optimisation technique. The numerical tests presented demonstrate the computational advantage of the proposed approach of ESs combined with functional networks (FNs) which become pronounced for fairly large scale optimisation problems involving about 700 degrees of freedom.

Custom cranioplasty using rapid prototyping technology.

Abstract: Sir,Cranioplasty for a large skull bone defect can be a challeng-ing surgical problem. A variety of materials have been usedfor cranioplasty. Due to the advances in bioengineering, cus-tom templates and prosthesis are now available for cranio-plasty using Rapid Prototyping (RP) technology. Rapidprototyping technology was originally developed to rapidlybuild a prototype of a new product, especially in automobileindustry. Now the same technology is used in the medical fieldin the production of anatomical models and templates, whichfacilitate surgeons to optimize preoperative surgical planning,interactive surgical simulation, while reducing operative timeand complications.TIFAC CORE (Technology Information, Forecasting andAssessment Council - Center of Relevance and Excellence),PSG College of Technology, Coimbatore provided the firstcustom template for cranioplasty in our patient. Under thebroad umbrella of technology vision-2020, TIFAC has set upa center of Relevance and Excellence in product design, opti-mization and collaborative product.

NFD technique for efficient and secured information hiding in low resolution images

Abstract: A new steganography algorithm that supports transmission of huge information with minimal embedding is proposed This approach uses the Newton's Forward Difference (NFD) Technique for mapping the text file/s onto a low resolution image file A polynomial function is derived to represent the mapping of the text bits with the bit positions on the host image file This polynomial is represented as bits and is embedded in the image file that is transmitted The bit replacements made in the host image file are negligible compared to those in the existing embedding techniques.

Dynamic Model for Flow and Droplet Deposition in Direct Ceramic Ink-jet Printing

Abstract: A rapid fabrication technique, for building microceramic parts, using a dropon-demand ceramic ink-jet printer is currently under development This finds application in producing ceramic cores for gas turbines, space applications, and ceramic hybrid electromechanical systems Another application is in the use of intelligent inks, in which particles assemble themselves so as to interrupt the signals in a particular direction and to produce a suitable output for tactical applications An attempt has been made to develo~a mathematical model for dro~leflo rmation from orifice and itsdewsition on subsmate The distributidn of energy supplied to the pi~zoelectrica ctuator in the ink-jet p&t head is modelled and ejected droplet parameters (diameter and velocity) were related to the force imparted by the piezodisc This model was extended to develop a relation for maxlmum droplet spread that occurs during impact h p l e t spread determines the lateral resolution of the system and the thickness of each deposited layer

A unique self-contained universal remote control

Abstract: Universal remote is a controlling device, which can perform all functions of different remotes of various brand appliances that are used in homes. At present, universal remotes do not stand up to their names, as they are not able to control all the devices. The universal remote proposed in this paper is self-contained and brand-independent in that it does not need a receiver unit to be fixed to the device nor does it expect the manufacturers to adhere to a code. The remote stores the code for different appliances in its memory and when a key is pressed retrieves the code from memory and processes it, unlike other remotes, which generate a code, every time a key is pressed.

A fast converging evolutionary neural network for the prediction of uplift capacity of suction caissons

Abstract: Evolutionary neural networks (ENN) with genetic algorithm (GA) based weight determination have lead to better performance aspects such as fast convergence or reduced learning error of the network, or better solutions when compared to their specific counterparts. In this investigation, we propose a scheme of GA based weight determination employing a genetic inheritance operator termed short term reproduction expectancy (STRE) which when embedded in the scheme results in a better performing ENN. The ENN employing the STRE scheme of inheritance (NEU/spl I.bar/GEN(STRE)) has been implemented and its performance compared with the same employing a generational GA for its weight determination (NEU/spl I.bar/GEN). The performance analysis has been demonstrated on the problem of prediction of uplift capacity of suction caissons in the field of geotechnical engineering.

Power flow control in FACTS

Abstract: The power flow control-using hybrid technique focuses on developing an approach to steady state power flow control of flexible AC transmission systems device equipped power system. In this paper unified power flow controller is used as a phase shifter and series compensator to regulate both angles and magnitude of branch voltages. Hybrid technique is a combination of evolutionary programming and sequential quadratic programming. The hybrid technique is developed in such a way that evolutionary programming is applied as a base level search, which can give a good direction to the optimal global region, and a local search sequential quadratic programming is used as a fine tuning to determine the optimal solution at the final. The algorithm is illustrated by using modified IEEE 30 bus system.

Efficient Identification Based on Human Iris Patterns.

Abstract: This paper proposes a person identification system (PID), which works with non-illumination low-resolution eye images. Radial-Scan and threshold methods are used for Iris normalization and Iris segmentation from the eye image respectively. Conventional neural network is used for iris matching. The proposed algorithm works with 96 features of the iris. Space complexity is less and Iris codes are stored in an encrypted file. The Algorithm has been implemented and tested on 1500 iris patterns. Images include normal iris captured under in-door and out-door conditions and from disease affected eyes.

Development of low cost, efficient residential utility interface for modular PV system with improved power quality

Abstract: This paper presents a high performance residential utility interface for photovoltaic (PV) system with DSP based control. The system is designed to realize high utilization efficiency and stability. The utilization efficiency is improved by using a new MPPT algorithm namely, three-point weight comparison method with dP/dD control. The overall efficiency is improved by using soft switching converters. The output power quality is improved by using unipolar sinusoidal pulse width modulation (SPWM) switching strategy. It reduces total harmonic distortion (THD) at the output and thereby improves the power quality. A 1/spl Phi/, 230 V, 200 W system was designed and implemented on a low cost DSP (TMS320C240). Maximum power point (MPP) tracking efficiency of 98% and THD of around 6% under full load conditions was achieved. The effectiveness of the proposed system has been confirmed by experimental results. Due to its simplified power stage and control stage, this system presents a better efficiency, lower cost and high reliability.

An Integrated Approach for Effective Supply Chain Management A Case Study of Amul

Abstract: This paper outlines the importance and benefits and an organization can achieve through supply chain integration. These benefits an primarily in the area of achieving superior customer service leve...