Showing papers by "Ghulam Ishaq Khan Institute of Engineering Sciences and Technology published in 2008"
TL;DR: The proposed decoding scheme is able to cope with the alterations in features introduced by a new attack and achieves promising improvement in terms of bit correct ratio in comparison to the existing decoding scheme.
87 citations
TL;DR: In this article, a 300-nm-thick film of methyl-red was deposited by a spin coater at an angular speed of 2000 revolutions per minute (RPM) on a glass substrate with preliminary deposited metal electrodes to form the Ag/methyl-red/Ag surface type cell.
Abstract: This paper describes the experimental results for humidity-dependent resistive and capacitive response of methyl-red thin films in a Ag/methyl-red/Ag surface-type cell. A 300-nm-thick film of methyl-red was deposited from 10 wt% solution in benzene by a spin coater at an angular speed of 2000 revolutions per minute (RPM) on a glass substrate with preliminary deposited metal electrodes to form the Ag/methyl-red/Ag surface-type cell. The length and width of the gap between the electrodes were 50 μm and 15 mm, respectively. The resistance of the film reduced from 37 to 17 MΩ with an elevation of relative humidity level over the whole humidity range. It was also observed that under the effect of humidity, the capacitance of the methyl-red thin film increased by 12 times. The capacitive/resistive sensor has a quasi-linear function with relative humidity in the range of 30–95% and has a small hysteresis. The response and recovery time of the sensor was about 10 s for the capacitive sensor. The humidity-dependent resistive and capacitive properties of this sensor make it promising for use in a humidity meter.
72 citations
01 May 2008
TL;DR: In this article, the performance of a gasketed flange joint is highly dependent on the proper joint assembly with prune-branching joints, and it is shown that gasketing bolted flange pipe joints are prone to leakage during operating conditions.
Abstract: Gasketed bolted flange pipe joints are found prone to leakage during operating conditions. Therefore, performance of a gasketed flange joint is highly dependent on the proper joint assembly with pr...
29 citations
TL;DR: A simple proximity based approach known as nearest neighbor (NN) is developed for classifying the 17 GPCRs subfamilies and shows that simple classification strategies may outperform complex ones because of the efficient exploitation of the feature space.
27 citations
TL;DR: A novel idea of employing genetic programming to obtain mathematical expressions representing the dependency of lattice constants (LC) on their atomic parameters is presented and it is revealed that only two atomic parameters are sufficient for LC prediction of GdFeO(3)-type perovskites.
Abstract: A novel idea of employing genetic programming to obtain mathematical expressions representing the dependency of lattice constants (LC) on their atomic parameters is presented in this paper. The results obtained from simulations reveal that only two atomic parameters are sufficient for LC prediction of GdFeO3-type perovskites. In addition, an advantage of this approach is that there is no need to save any trained model as in the case of other existing machine-learning based approaches.
19 citations
Journal Article•
TL;DR: A thin organic films of p-type semiconducting copper phthalocynanine (CuPc) film and semitransparent Al film were deposited in sequence by vacuum evaporation on glass substrate with Ag source and drain electrodes as discussed by the authors.
Abstract: A thin organic films of p-type semiconducting copper phthalocynanine (CuPc) film and semitransparent Al film were deposited in sequence by vacuum evaporation on glass substrate with Ag source and drain electrodes, fabricating an organic field effect transistor with metal (aluminum)-semiconductor (copper phthalocyanine) Schottky junction The transistor was investigated for effect of illumination on its characteristics It was found that the gate-source (Al-Ag) and gate-drain (also Al-Ag) dark currentvoltage characteristics show rectification behavior Under non-modulated filament-lamp illumination, photo-potential is developed between gate-source and gate-drain terminals Drain current of this organic phototransistor (OPT) increased with illumination An energy band diagram of the Al-CuPc junction and the equivalent circuit diagram of the OPT were produced
11 citations
TL;DR: In this article, the proper projective collineation in non-static spherically symmetric space-times using direct integration and algebraic techniques is investigated, and it is shown that the space times which admit proper collineations turn out to be very special classes of static SPHSPs.
Abstract: We investigate the proper projective collineation in non-static spherically symmetric space-times using direct integration and algebraic techniques. Studying projective collineation in the above space-times, it is shown that the space-times which admit proper projective collineations turn out to be very special classes of static spherically symmetric space-times.
7 citations
TL;DR: In this paper, an analytical expression for the effective permeability of inner ring shorted split ring resonator is derived and the resonant frequencies are compared with published results and good agreement is observed for higher split lengths.
Abstract: Analytical expression for effective permeability of inner ring shorted split ring resonator is derived in this paper. The resonant frequencies thus calculated are compared with published results and good agreement is observed for higher split lengths. Simulation results for effective permeability with different gap lengths in the split ring resonator are also included in this paper. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 624–627, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23149
5 citations
30 Mar 2008
TL;DR: The experimental results on standard texture and color datasets show that the proposed image retrieval system (SVMBIR) has superior retrieval performance over the existing linear feature combining techniques.
Abstract: This paper presents a novel image retrieval system (SVMBIR) based on dual tree complex wavelet transform (CWT) and support vector machines (SVM). We have shown that how one can improve the performance of image retrieval systems by assuming two attributes. Firstly, images that user needs through query image are similar to a group of images with same conception. Secondly, there exists non-linear relationship between feature vectors of different images and can be exploited very efficiently with the use of support vector machines. At first level, for low level feature extraction we have used dual tree complex wavelet transform because recently it is proven to be one of the best for both texture and color based features. At second level to extract semantic concepts, we grouped images of typical classes with the use of one against all support vector machines. We have also shown how one can use a correlation based distance metric for comparison of SVM distance vectors. The experimental results on standard texture and color datasets show that the proposed approach has superior retrieval performance over the existing linear feature combining techniques.
5 citations
01 Oct 2008
TL;DR: In this article, a path loss prediction model for line-of-sight communication at microwave frequency is proposed, which incorporates the effects of obstacles like vegetation and vehicular traffic present in actual urban environment.
Abstract: Path loss prediction model for line-of-sight communication at microwave frequency is proposed in this paper. The proposed model incorporates the effects of obstacles like vegetation and vehicular traffic present in actual urban environment. Loss layer model is used to include the effect of trees while average height model employs the traffic effect in propagation loss. These two models are incorporated into two ray model to predict the path loss in microcellular environment. Simulations are carried out and results show good agreement with measurements published in literature.
4 citations
TL;DR: In this article, the structures of mixed LB films of silane-coupling agents with polymerization initiating groups (SCA-PIGs) and conventional amphiphiles such as long-chain fatty acid and hybrid carboxylic acid having both perfluoroalkyl and alkyl moieties were studied.
Posted Content•
TL;DR: In this article, a study of proper conformal vector field in non conformally flat cylindrically symmetric static space-times is given by using direct integration technique, and it is shown that a very special class of the above space-time admits proper vector field.
Abstract: A study of proper conformal vector field in non conformally flat cylindrically symmetric static space-times is given by using direct integration technique. Using the above mentioned technique we have shown that a very special class of the above space-time admits proper conformal vector field.
01 May 2008
TL;DR: In this article, an experimental and numerical study was carried out to predict the crack growth rate under fatigue loading in a thick-walled cylinder made of aluminum alloy, and the results obtained from the two techniques were in good agreement up to a stress range of 79 MPa, but the number of cycles to failure as determined by FE analysis (FEA) was smaller than found experimentally.
Abstract: Experimental and numerical studies were carried out to predict the crack growth rate under fatigue loading in a thick-walled cylinder made of aluminum alloy. Extensive experimental fatigue-crack growth data on middle tension samples was compiled and applied to simulate and predict the crack growth process using detailed two-dimensional parametric finite-element (FE) technique. The fatigue-crack propagation was simulated, based on linear elastic fracture mechanics and stress intensity factor determination. The FE model provided results of crack- growth analysis optimized for stress levels ranging from 40 per cent to 25 per cent of the material yield stress. Fatigue-life analysis of the samples showed that the results obtained from the two techniques were in good agreement up to a stress range of 79 MPa. However, at lower stress ranges, the number of cycles to failure as determined by FE analysis (FEA) was smaller than found experimentally. The experimental results were 13 per cent and 36 per cent higher than FEA results at stress ranges of 63 and 49 MPa, respectively. This disparity was explained in terms of the crack growth rates near the threshold stress intensity factor range.
25 Mar 2008
TL;DR: In this paper, a comparative analysis of these preprocessing techniques is presented, and it is clearly seen that the distortion of the modified AM is greatly reduced from the normal AM, and simulation results show the effectiveness of the preprocessing methods.
Abstract: A highly focused sound beam can be created from the nonlinear interaction of ultrasound waves by using a parametric loudspeaker. An audio signal is produced by the self-demodulation of amplitude modulated sound waves in air. Several preprocessing techniques have been discussed in previous literature to reduce distortion. A comparative analysis of these preprocessing techniques is presented in this paper. Some preceding preprocessing techniques rely on equalization and square-rooting. Newer techniques, instead of using only simple AM, have an additional AM signal with a carrier that is orthogonal to the original one. It will be clearly seen that the distortion of the modified AM is greatly reduced from the normal AM. Simulation results show the effectiveness of the preprocessing techniques.
25 Mar 2008
TL;DR: Using both analysis and extensive simulations, it is shown that the proposed dynamic routing help achieve the desired system performance under the dynamically changing network conditions.
Abstract: In Wireless Sensor Network (WSN), the sensors have limitations like energy-constrained nodes, unreliable links, and frequent topology change. In this paper we are trying to propose a routing protocol, which gives better results than any other conventional protocols. The protocol based on Logical Network Abridgement (LNA), used to measure the underlying path diversity and intrinsic network resiliency to congestion, failures and attacks. The proposed protocol focuses on vulnerability index and energy awareness of the node. Using both analysis and extensive simulations, we show that the proposed dynamic routing help achieve the desired system performance under the dynamically changing network conditions.
01 Feb 2008
TL;DR: In this article, a non-gasketed flange joint with different flange surface profiles (positive taper, negative taper and zero taper angles) is analyzed to find out the most optimal flange geometry for safe stress and no-leak conditions under bolt up and internal pressure loading.
Abstract: Performance of a flange joint is characterized mainly due to its ‘strength’ and ‘sealing capability’. Available design rules for flange joints are mainly concerned with the strength of the flanges and do not sufficiently consider for their sealing. Being continuous problems faced by the gasketed flange joints for strength and sealing based on concluded ‘dynamic mode of load’, non-gasketed joints are recommended as an alternative. The current paper presents three-dimensional non-linear finite-element analysis of non-gasketed flange joint with different flange surface profiles (positive taper, negative taper, and zero taper angles) to find out the most optimal flange geometry for safe stress and no-leak conditions under bolt up and internal pressure loading. Based on the results, optimum flange geometry is selected and further analysed under proof test pressure. A ‘static mode of load’ in positive taper angle flange is concluded, ensuring proper joint sealing, and strength.
01 Jan 2008
TL;DR: Experimental verifications indicate that the proposed unified image watermarking is an appropriate choice.
Abstract: A novel approach for color image watermarking is proposed in this communication. The aim of the work is to combine robust and fragile watermarking in order to construct a multipurpose watermarking scheme. Watermarking methods are com- plementing each other such that under any circumstance at least one of them may survive and prove the identity of the owner or the authenticity of the image content. A robust watermark is embedded into the frequency domain; the watermark is made adaptive to the cover image. A semi-fragile watermark is embedded into the spatial domain of the color image. Authentication is achieved by means of embedding an approximation of the image into itself. Specifically, the luminance of the image is inserted into the three color channels, using a mapping function. For image copyright protection, higher robustness can be achieved whereas for image authentication tampered regions can be detected and reconstructed. Both of the goals are accomplished in an oblivious manner. Experimental verifications indicate that the proposed unified image watermarking is an appropriate choice.
TL;DR: In this paper, the multi-walled carbon nanotubes (CNTs) reinforced copper matrix nanocomposites were synthesized by a chemical-based route commonly known as molecular level mixing.
Abstract: This work presents the multi-walled carbon nanotubes (CNTs) reinforced copper matrix nanocomposites that were synthesised by a chemical based route commonly known as molecular level mixing. These nanocomposites can exhibit much superior properties as compared to other metal matrix composites. A copper acetate monohydrate sample was mixed with CNTs in ethanol followed by drying, calcination, and reduction. This resulted in the formation of copper nanoparticles attached with uniformly dispersed CNTs. The samples at each process step were characterised by using Fourier transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), and scanning electron microscopy (SEM). Emphasis is placed on the functionalisation of the CNTs and its role in deagglomeration in order to achieve uniform mixing with the copper metal matrix. Sintering of the powder was done at 900°C for two hours and SEM studies revealed good retention and uniform distribution of CNTs in the copper-based matrix of the nanocomposite samples indicating considerable benefits of the synthesis process.
01 May 2008
TL;DR: In this paper, the fabrication and electrical characterization of surface type Al/methyl-red/Ag Schottky barrier diode was reported, where electrodes were deposited on glass substrate with a narrow gap between them followed by spin coating of methyl-red (MR).
Abstract: :This paper reports the fabrication and electrical characterization of surface typeAl/methyl-red/Ag Schottky barrier diode. Electrodes were deposited on glass substratewith a narrow gap between them followed by spin coating of methyl-red (MR). A thinfilm of MR was deposited from 10 wt% solution in benzene by spin coater at an angularspeed of 2000 revolution per minute (RPM) on a glass substrate with preliminarydeposited metal electrodes. The thickness of the film was 300 nm. The length and widthof the semiconducting channel between metallic electrodes were equal to 30 m and 17mm, respectively. The current-voltage (I-V) characteristics of Al/MR/Ag structureshowed rectification behavior. The value of rectification ratio was found about 200 at ±4V. I-V characteristics of Al/MR/Ag structure were also investigated as a function oftemperature ranging from 25-55 °C. The sample was also investigated as humiditysensor at room temperature within the relative humidity (RH) range of 30-90%. Theimpedance changed linearly and approximately reduced 5 orders of magnitude over thewhole humidity range. It was observed that under the effect of humidity the capacitanceof the MR film increased by 1.5 times over the whole humidity range.