Probabilistic Verification Scenarios with Reduced Authentication Delay for Handoff Clients in Mesh Networks

Wireless Personal Communications - In this paper, we have proposed a secure handoff procedure by generating and assessing the tickets for each mesh client which are divided among various zones of...     

PSO-optimized Pareto and Nash equilibrium gaming-based power allocation technique for multistatic radar network

At present, multiple input multiple output radars offer accurate target detection and better target parameter estimation with higher resolution in high-speed wireless communication systems. This study focuses primarily on power allocation to improve the performance of radars owing to the sparsity of targets in the spatial velocity domain. First, the radars are clustered using the kernel fuzzy C-means algorithm. Next, cooperative and noncooperative clusters are extracted based on the distance measured using the kernel fuzzy C-means algorithm. The power is allocated to cooperative clusters using the Pareto optimality particle swarm optimization algorithm. In addition, the Nash equilibrium particle swarm optimization algorithm is used for allocating power in the noncooperative clusters. The process of allocating power to cooperative and noncooperative clusters reduces the overall transmission power of the radars. In the experimental section, the proposed method obtained the power consumption of 0.014 to 0.0119 at K = 2, M = 3 and K = 2, M = 3, which is better compared to the existing methodologies—generalized Nash game and cooperative and noncooperative game theory.     

Liquid crystal polymer-carbon fiber composites. Molecular orientation

The objective of this work has been to study composite systems in which carbon fibers are dispersed in a liquid crystal polymer matrix. The fundamental point of interest here has been the interfacial response that fiber surfaces can potentially induce in self-ordering polymers. The matrix material used was a thermotropic liquid crystal polyester synthesized in our laboratory from the monomers p-acetoxybenzoic acid, diacetoxyhydroquinone, and pimelic acid. The aromatic-aliphatic polymer was characterized by NMR as a chemically disordered polymer of the three structural units which exhibits a nematic phase at temperatures above 150°C. Breadline proton NMR above the solid to liquid crystal transition was used to measure the rate of magnetic alignment of molecules in the matrix and polarized optical microscopy was used to analyze interfacial zones in composite samples. Fiber surfaces were found to influence the orientation and orientational dynamics of a liquid crystal polymer matrix. This was revealed by enhanced rates of magnetic orientation in the polymer melt when carbon fibers are dispersed in the medium. Fiber surfaces were also found to stabilize nematic ordering of the polymer as the melt was heated towards complete isotropization. The phenomena discovered here may originate in the development of zones around fibers with a common molecular orientation anchored by the carbon surface.     

Trace anomalies as precursors of field failures: an empirical study

Reproducing and learning from failures in deployed software is costly and difficult. Those activities can be facilitated, however, if the circumstances leading to a failure can be recognized and properly captured. To anticipate failures we propose to monitor system field behavior for simple trace instances that deviate from a baseline behavior experienced in-house. In this work, we empirically investigate the effectiveness of various simple anomaly detection schemes to identify the conditions that precede failures in deployed software. The results of our experiment provide a preliminary assessment of these schemes, and expose the tradeoffs between different anomaly detection algorithms applied to several types of observable attributes under varying levels of in-house testing.

Inferior myocardial infarction detection using stationary wavelet transform and machine learning approach

Early and accurate detection of myocardial infarction is imperative for reducing the mortality rate due to heart attack. Present work proposes a novel technique aiming toward accurate and timely detection of inferior myocardial infarction (IMI). Stationary wavelet transform has been used to decompose the segmented multilead electrocardiogram (ECG) signal into different sub-bands. Sample entropy, normalized sub-band energy, log energy entropy, and median slope calculated over selected bands of multilead ECG are used as features. Support vector machine (SVM) and K-nearest neighbor (KNN) have been used to classify between subjects admitted for health control (HC) and patients suffering from IMI, using attributes selected on the basis of gain ratio. The full length ECG of lead II, III, and aVF of all the subjects having IMI or admitted for HC from Physikalisch-Technische Bundesanstalt Database (PTB-DB) has been used in the present work. The proposed technique has been scrutinized under both “class-oriented,” and more practical, “subject-oriented” approach. Under the class-oriented approach, data have been divided into training and test data irrespective of the patients, whereas in subject-oriented approach, data from one patient have been used for test and training has been done on the rest of the subjects. Under the class-oriented approach, area under the receiver operating characteristic curve (Roc), sensitivity (Se%), specificity (Sp%), positive predictivity (+P%), and accuracy (Ac%) is Roc \(=\) 0.9945, Se% \(=\) 98.67, Sp% \(=\) 98.72, +P% \(=\) 98.79, Ac% \(=\) 98.69 using KNN and Roc \(=\) 0.9994, Se% \(=\) 99.35, Sp% \(=\) 98.29, +P% \(=\) 98.41, Ac% \(=\) 98.84 using SVM. For the subject-oriented approach, an average Ac% \(=\) 81.71, Se% \(=\) 79.01, Sp% \(=\) 79.26, and +P% \(=\) 80.25 has been achieved. This shows the potential of the proposed technique to work for an unknown subject, on which it has not been trained.     

Dietary fats rich in saturated fatty acids (12∶0, 14∶0, and 16∶0) enhance gallstone formation relative to monounsaturated fat (18∶1) in cholesterol-fed hamsters

To test the possibility that dietary palmitic acid (16∶0) may be lithogenic, different fats were blended to exchange 18∶1 in olive oil with either 16∶0 in palm stearin, 12∶0+14∶0 in coconut oil, or 14∶0+16∶0 in butterfat. Dietary 18∶2 was held constant at 1.2% energy (en) (with extra safflower oil as needed) in these four purified diets containing low fat (11% of total energy) and 0.4% cholesterol. A fifth, high-fat diet provided 40% of the total energy as the 16∶0-rich blend. All hamsters fed the low-fat, 16∶0-rich blend for six weeks developed cholesterol gallstones (8/8). Although the gallstone incidence was lower for the 12∶0+14∶0-rich diet (5/8), the severity of stone formation in affected hamsters was equal to that in the low-fat, 16∶0-rich group. Mucin accumulation in gallbladder bile was often associated with cholesterol gallstones in diets containing 16∶0, but was minimal in 18∶1-rich and 12∶0+14∶0-rich groups. Neither the lithogenic index (all>1.0), plasma lipids, nor liver cholesterol was a selective predictor of stone formation. The high-fat, 16∶0-rich diet actually decreased cholesterol stone incidence (3/8) and severity, but yielded a high incidence of pigment stones (5/8). Thus, saturated fat and 16∶0per se were not responsible for the exaggerated lithogenesis. Because the antilithogenic 18∶1-rich diet also normalized the 18∶2 intake (1.2% en) relative to previous butter diets (0.3% en), the potential importance of essential fatty acids (EFA) deficiency in the model was tested in a second study by feeding graded amounts of 18∶2 (0.3, 0.6, 0.9, and 1.2% en) as safflower oil in four low-fat, butter-rich diets (11% en as fat) without alleviating gallstone incidence or severity. These studies indicate that substitution of 18∶1 for saturated fatty acids in low-fat diets reduces gallstone formation without affecting the lithogenic index. Furthermore, intake of 18∶2 at or below the EFA requirement does not appear to be a major factor in this model.     

Graft copolymerization of acrylamide on cotton cellulose in a limited aqueous system following pretreatment technique

Graft copolymerization of acrylamide on cotton (dialdelyde cellulose, DAC) fibers and fabrics was studied in a limited aqueous system using K₂S₂O₈ as the initiator. Grafting parameters under different sets of conditions were determined and the mechanism of graft copolymerization discussed. Optimum conditions for grafting were established and the effect of polyacrylamide grafting on tenacity, modulus, breaking elongation, and stiffness of the cotton (DAC) fabrics and on their dyeability and moisture regain properties were also studied; 9–10% grafting of polyacrylamide on (DAC) fabric at _pH 7–10 imparts an improved balance in its mechanical and other properties. © 1995 John Wiley & Sons, Inc.     

Transesterification of karanja (Pongamia pinnata) oil by solid basic catalysts

The transesterification of karanja oil with methanol was carried out using solid basic catalysts. Alkali metal‐impregnated calcium oxide catalysts, due to their strong basicity, catalyze the transesterification of triacylglycerols. The alkali metal (Li, Na, K)‐doped calcium oxide catalysts were prepared and used for the transesterification of karanja oil containing 0.48–5.75% of free fatty acids (FFA). The reaction conditions, such as catalyst concentration, reaction temperature and molar ratio of methanol/oil, were optimized with the solid basic Li/CaO catalyst. This catalyst, at a concentration of 2 wt‐%, resulted in 94.9 wt‐% of methyl esters in 8 h at a reaction temperature of 65 °C and a 12 : 1 molar ratio of methanol to oil, during methanolysis of karanja oil having 1.45% FFA. The yield of methyl esters decreased from 94.9 to 90.3 wt‐% when the FFA content of karanja oil was increased from 0.48 to 5.75%. The performance of this catalyst was not significantly affected in the presence of a high FFA content up to 5.75%. The catalytic activities of Na/CaO and K/CaO were also studied at the optimized reaction conditions. In these two cases, the reaction initially proceeds slowly, however, leading to similar yields as in the case of Li/CaO after 8 h of reaction time. The purified karanja methyl esters have an acid value of 0.36 mg KOH/g and an ester content of 98.6 wt‐%, which satisfy the American as well as the European specifications for biodiesel in terms of acid value and ester content.     

Optimization of the polycondensation step of polyethylene terephthalate formation with continuous removal of condensation products

The polycondensation step of poly(ethylene terephthalate) (PET) formation is assumed to include various side reactions in addition to the usual polymerization reaction. Polymerization in the batch reactor at constant pressure has been modeled to flash volatile components at the end of small discrete time intervals with polymerization occurring during the interval. The Hamiltonian has been written for the time interval and optimum temperature history computed for batch reactors for various reactor pressures. For low pressures, computed optimum temperature history is found to be of similar nature as that used in industry.     

Utilization of treated spent liquor sludge with fly ash in cement and concrete

Design mix of M-20 concrete was prepared in the laboratory by substituting cement with the treated spent liquor sludge (TSLS) and fly ash. During the study, TSLS is fixed at 7.5% by weight, and fly ash is varied as 5%, 10%, 15%, 20% and 25% to study the possibility of replacement of cement. A 15% fly ash gives the optimum compressive strength. Addition of fly ash has resulted in complete removal of toxicity as per US EPA toxicity characteristic leaching procedure (TCLP) test. A total of 7.5% sludge and 15% fly ash in M-20 concrete is expected to save Rs. 252/m³ (≈USD 5.3/m³⁾ of concrete.