A Dynamical Systems Approach to a Thin Accretion Disc and its Time-dependent Behaviour on Large Length Scales
- Arnab K. Ray and Jayanta K. Bhattacharjee
Contact: arnab.kumar@juet.ac.in; jkb@hri.res.in
Abstract :Modelling the flow in a thin accretion disc like a dynamical system, we analyse the nature of the critical points of the steady solutions of the flow. For the simple inviscid disc there are two critical points, with the outer one being a saddle point and the inner one a centre type point. For the weakly viscous disc, there are four possible critical points, of which the outermost is a saddle point, while the next inner one is a spiral. Coupling the nature of the critical points with the outer boundary condition of the flow, gives us a complete understanding of all the important physical features of the flow solutions in the subsonic regions of the disc. In the inviscid disc, the physical realisability of the transonic solution passing through the saddle point is addressed by considering a temporal evolution of the flow, which is a very likely non-pertunbative mechanism for selecting the transonic inflow solution from among a host of other possible stable solutions. For the weakly viscous disc a linearised time-dependent perturbation imposed on the steady mass inflow rate causes instability. The same perturbative analysis reveals that for the inviscid disc there is a very close correspondence between the equation for the propagation of the perturbation and the metric of an acoustic black hole. Compatible with the transport of angular momentum to the outer regions of the disc, a viscosity-limited length scale is defined for the spatial extent of the inward rotational drift of matter. 

A J2ME Based Credit Card Number Verification Software Using Bluetooth
- Meenakshi Nainwal, Nishant Gupta and Rahul Johari
Contact: meenakshinainwal@live.com; nishant.gupta1988@yahoo.com;rahuljohari@hotmail.com
Abstract: This paper describes the use of Java 2 Platform, Micro Edition to develop a credit card number verification software using Bluetooth. With the extensive use of mobile devices and proliferation of wireless technology in day-to-day life, the proposed software can be easily adapted at various retail shops and can make creditcard number verification process fast and convenient for users. The basis of the proposed method is KVM, an optimized Virtual Machine for mobile devices limited by memory, power consumption and connectivity, and JSR82 (Java Specification Requests 82: Bluetooth API). A secure client-server relationship is established between two mobile devices. The client side device at the customer end passes the credit card details through Bluetooth to the server side device with the retailer. The server side verifies the details. Sun JavaME Wireless Toolkit 2.5.2 is used to automate tasks related to creation and testing of the proposed software and the results are effectively shown. Also the comparison between using J2ME and Android as a development platform is also discussed.

Efficient Timing Estimation Algorithm for OFDM Systems
- P.K. Singh, U. Mathur, N. Bhasker, Hem Dutt joshi, Vinay Kumar and Rajesh Khanna
Contact: hemdutt@gmail.com
Abstract: In this paper, a new algorithm for timing offset estimation is proposed in an OFDM system. The proposed algorithm uses a short preamble and employs cross correlation instead of auto-correlation and reverse auto-correlation as given in past to reduce the effect of noisy channels. The performance of the proposed scheme is compared with other available algorithms in terms of mean and mean-square error (MSE). The simulation results show that the proposed estimator performs better than other available estimator in literature.

Vibration Analysis of Imprecisely Defined Circular Plates
- S. Chakraverty and Rajni
Contact: sne_chak@yahoo.com
Abstract: Dynamics of circular plates have already been studied by many authors by various methods. Very recently vibration analysis of imprecisely defined bars, beams and other simple structures have been investigated by few authors. Present paper investigates vibration analysis of imprecisely defined circular plates. As such the corresponding problem has been solved using Rayleigh Ritz method, where the mass and stiffness matrices are in interval or fuzzy form. Thus the corresponding interval or fuzzy generalized eigenvalue problems are solved to get the interval or fuzzy natural frequencies of the circular plate. The results obtained have been compared for different special cases and they show a good agreement.

Fuzzy Matrix Solution for the Study of Teacher’s Evaluation
- Vivek Raich; Archana Gawande and Seema Modi
Contact: drvivekraich@gmail.com; gawandearchana@gmail.com
Abstract: Researchers who study teacher quality put a great interest in investigating the quality of effective teacher. A number of policy makers and researchers have proposed that effectiveness, as determined by teachers’ contribution to student learning, should be an important component of assessing teacher quality. Therefore, teacher quality measurement is important. Fuzzy relation provides solutions of our daily life problems depend on two different situations. In this paper, we try to obtain conclusion about teachers performance by giving membership grades to his/her quality from 0 to 1 in the fuzzy relation matrix Ro (an occurrence relation obtained by observations on sufficient number of teacher), Rc (a conformability relation confirmed by expert in education sector) and Rs (a matrix which contains degree of specialty seen by educationist for testing the model).

Selection of Optimum Machining Parameters For EN31 Alloy Steel in CNC Turning Using Taguchi Method
- Kaushal Pratap Singh and Gavendra Norkey
Contact: kp92dit@yahoo.com; gavendra.norkey@juet.ac.in
Abstract: In this research work, L16 orthogonal array based on Taguchi optimization technique is used to optimize the effect of various cutting parameter for surface roughness and Material Removal Rate (MRR) of EN 31 work material in turning operation. The orthogonal array, signal to noise ratio and analysis of variance are employed to study the performance characteristics of cylindrical work pieces using Tin coated tungsten carbide cutting tool on CNC lathe. Four machining parameters such as spindle speed, feed rate, depth of cut and nose radius are optimized with consideration of surface roughness and MRR. Results of this study indicate for optimal cutting parameters, minimum surface roughness (Ra) and maximum material removal rate were obtained and developed model can be used to increase the machine utilization at low production cost in manufacturing environment.

Reconstruction Methods for Accurate Measurement of Heavy-duty Emissions
- Madhava R. Madireddy
Contact: madhava.madireddy@vito.be
Abstract: Currently, heavy-duty diesel engines can be certified for emissions measured in a thirty second time window with certain specification requirements for the analyzers. But if an analyzer is used to measure emissions, it gives out a response that may not reflect the true engine-out emissions and the integrated values for the thirty second windows may be affected by analyzer response. This paper presents methods in which the true instantaneous emissions can be reconstructed. Obtaining instantaneous emissions could go a long way in devising better engine control strategies and developing emissions inventory models. Three methods of reconstruction studied in this paper were Differential Coefficients Method (DCM), Inverse Fast Fourier Transform (IFFT) and Modified Deconvolution Technique (MDT). The application of each method in reconstructing real-time emissions data was presented. Each of the three methods was shown to offer advantage in the post-processing of the measured emissions data. Continuous data of power was assumed to be instantaneous and the correlation of reconstructed emissions with power was considered a yard stick to estimate the reliability of the method. While DCM or IFFT were used, the correlation of power for the reconstructed emissions was on an average 2% more than the correlation of the power with measured emissions. The corresponding improvement with MDT was 3%.
 

Design Investigations on Improved Wood Cooking Stove for Rural India
- S.K. Shukla and Ajay Tripathi
Contact: trip2ajay@gmail.com; ajay.tripathi@juet.ac.in
Abstract: Cooking is as essential requirement of all households. Most of the food products need application of heat to become edible. Of the total energy consumed in India, nearly 40 percent is by non-conventional energy sources by way of firewood, animal dung cake, agro-forestry waste and to a small extent biogas. Most of the energy need in rural areas i.e., 65% to 80% for cooking purpose is being met by way of non-conventional energy sources. Therefore, forest is being fast depleted to meet the basic energy need to rural house-wives. It is estimated that against an annual requirement of 133 million tons of firewood, only 49 million tones are forthcoming. The situation in future will be more desperate unless vigorous measures are taken to harness all sources of renewable energy and to conserve the energy sources.

 

Stimuli Responsive Smart Polymeric Hydrogel for Controlled Release
- Swapnali Hazarika
Contact: shrrljt@yahoo.com
Abstract: Stimulus responsive poly (N-isopropylacrylamide-co-benzo-[18]-crown-6-acrylamide) hydrogel was synthesised using a crown ether derivative benzo-[18]-crown-6-acrylamide (BCAm) by copolymerization with N-isopropylacrylamide in a mixed solvent of water and tetrahydrofuran and characterized by FTIR and Scanning Electron Microscopic analysis. BCAm was prepared from Aminobenzo-18-crown-6 and triethylamine and characterized. In the polymerization reaction 80%-85% conversion was obtained. Swelling behaviour of convensional and PEG modified hydrogel was studied and observed that after reaching Low Critical Solution Temperature (LCST), the swelling ratio of the hydrogel decreases and phase separation occurs. With increasing the concentration of BCAm in the hydrogel the swelling ratio decreases at low temperature. Swelling ratio increases with addition of PEG in the hydrogel. Deswelling kinetics of the hydrogel was established and observed that the hydrogel lost approximately 85% of their original water content within 4 minutes and quickly reached their stable position within 6-8 minutes. Conventional and PEG modified hydrogel were used for control release of Vitamin B considering NaCl as the environmental solution and observed that release rate increases when PEG modified hydrogel was used. Release rate of the vitamin B was found to be pH dependent.

 

Predictions with Intuitionistic Fuzzy Soft Sets
- Sylvia Encheva
Contact: sbe@hsh.no
Abstract: This paper is applying methods from soft sets theory for timely identification of students who are in danger to fail their exam in a particular subject. The work exploits the advantages of soft sets compare to fuzzy logics and statistical methods. While most statistical methods require large data sets and perform well in stochastically stable environments, the ones we have been addressing in this paper can give results within a very small data sets and can accommodate additional information derived from later experiments.

Some Applications of Intuitionistic Fuzzy Sets for the Determination of a Sociometric Index of Acceptance
- Piotr Dworniczak
Contact: p.dworniczak@ue.poznan.pl
Abstract: A simple use of intuitionistic fuzzy sets to determine and process the information describing the level of acceptance of people in a social group (e.g., pupils in a school class) is presented in the paper. An algorithm of processing linguistic assessments is given that leads to aggregated opinions and conclusions in the form of linguistic evaluation.