Operating insurance [computer system protection]

The protection of small computer systems against power line disturbances is addressed. The sources of these disturbances are identified, and the consequences are described. The use of surge suppressors and uninterruptible power supplies is discussed     

A novel frequency-domain model for a parallel-resonant converter

A steady-state analysis of the parallel-resonant converter is presented using a novel frequency-domain model. Various circuit variables are determined by simple expressions for both the frequency and the phase control techniques, simplifying the steady-state analysis. The existence of a multiple conduction mode is pointed out. The variations of output voltage, turn-off time, output power, and converter efficiency are studied     

A new relaxation algorithm and passive sensor data association

The static problem of associating measurements at a given time from three angle-only sensors in the presence of clutter, missed detections, and an unknown number of targets is addressed. The measurement-target association problem is formulated as one of maximizing the joint likelihood function of the measurement partition. Mathematically, this formulation leads to a generalization of the 3-D assignment (matching) problem, which is known to be NP hard. The solution to the optimization problem developed is a Lagrangian relaxation technique that successively solves a series of generalized two-dimensional (2-D) assignment problems. The algorithm is illustrated by several application examples     

Bonsai: diverse and shallow trees for extreme multi-label classification

Machine Learning - Extreme multi-label classification (XMC) refers to supervised multi-label learning involving hundreds of thousands or even millions of labels. In this paper, we develop a suite...     

A novel three-band orthogonal wavelet filter bank method for an automated identification of alcoholic EEG signals

Alcoholism is a critical disorder related to the central nervous system, caused due to repeated and excessive consumption of alcohol. The electroencephalogram (EEG) signals are used to depict brain activities. It can also be employed for diagnosis of subjects consuming excessive alcohol. In this study, we have developed an automated system for the classification of alcoholic and normal EEG signals using a recently designed duration-bandwidth product (DBP), optimized three-band orthogonal wavelet filter bank (TBOWFB), and log-energy (LE). First, we obtain sub-bands (SBs) of EEG signals using the TBOWFB. Then, we use logarithms of the energies of the SBs as the discriminating features which are fed to the least square support vector machine (LS-SVM) for the discrimination of normal and alcoholic EEG signals. We have achieved a classification accuracy (CA) of 97.08%, with ten-fold cross validation strategy. The proposed model presents a promising performance, and therefore it can be used in a practical setup to assist the medical professionals in the diagnosis of alcoholism using EEG signals automatically.     

Chaotic cuckoo search

This study proposes a novel chaotic cuckoo search (CCS) optimization method by incorporating chaotic theory into cuckoo search (CS) algorithm. In CCS, chaos characteristics are combined with the CS with the intention of further enhancing its performance. Further, the elitism scheme is incorporated into CCS to preserve the best cuckoos. In CCS method, 12 chaotic maps are applied to tune the step size of the cuckoos used in the original CS method. Twenty-seven benchmark functions and an engineering case are utilized to investigate the efficiency of CCS. The results clearly demonstrate that the performance of CCS together with a suitable chaotic map is comparable as well as superior to that of the CS and other metaheuristic algorithms.     

Java application for the superposition T-matrix code to study the optical properties of cosmic dust aggregates

In this paper, we report the development of a java application for the Superposition T-matrix code, JaSTA (Java Superposition T-matrix App), to study the light scattering properties of aggregate structures. It has been developed using Netbeans 7.1.2, which is a java integrated development environment (IDE). The JaSTA uses double precession superposition codes for multi-sphere clusters in random orientation developed by Mackowski and Mischenko (1996). It consists of a graphical user interface (GUI) in the front hand and a database of related data in the back hand. Both the interactive GUI and database package directly enable a user to model by self-monitoring respective input parameters (namely, wavelength, complex refractive indices, grain size, etc.) to study the related optical properties of cosmic dust (namely, extinction, polarization, etc.) instantly, i.e., with zero computational time. This increases the efficiency of the user. The database of JaSTA is now created for a few sets of input parameters with a plan to create a large database in future. This application also has an option where users can compile and run the scattering code directly for aggregates in GUI environment. The JaSTA aims to provide convenient and quicker data analysis of the optical properties which can be used in different fields like planetary science, atmospheric science, nano science, etc. The current version of this software is developed for the Linux and Windows platform to study the light scattering properties of small aggregates which will be extended for larger aggregates using parallel codes in future.     

Studies on interpenetrating polymer networks based on nitrile rubber-poly(vinyl chloride) blends and poly(alkyl methacrylates)

Several interpenetrating polymer networks (IPNs) based on nitrile rubber-poly(vinyl chloride) blends and various alkyl methacrylates have been synthesized. The rubber blends were swollen in methacrylate monomers containing required amounts of initiator and crosslinker for specific time periods and then polymerized at higher temperature. The composition of the IPNs could be varied by changing the swelling time. The IPNs were characterized for their glass-transition temperature, dynamic mechanical properties, and tensile properties. The effect of structure and composition on the vibration damping characteristics of these IPNs are discussed. © 1994 John Wiley & Sons, Inc.     

Studies on tributyl tin methacrylate II. Temperature dependence of the polymerization of tributyl tin methacrylate

In continuation of the earlier communication, we report here a detailed kinetic analysis of the polymerization of tributyl tin methacrylate initiated by azobisisobutyronitrile at the temperature range of 50–80°C. The initiator exponents are found to vary with temperature and viscosity of the medium reaching a low value of 0.40 at 50°C. This has been explained as due to primary radical termination which is very important in this system particularly at low temperatures. Energy of activation of viscous flow for this monomer is found to be approximately 4.2 kcal/mol which is substantially higher than for methyl methacrylate. The energy of activation for propagation has been determined applying the procedure of Fischer and Schulz and is 4.6 kcal/mol which is quite comparable to that of methyl methacrylate. The faster rate of polymerization of this monomer compared to other methacrylates has been attributed to lower rate of termination because of steric hindrance and viscosity effects. The energy of activation for initiation in this monomer seems to be quite high and comparable to values obtained for other vinyl monomers.