Automatic object tracking in optimized UAV video

The Journal of Supercomputing - Target detection and tracking in unmanned aerial vehicle (UAV) surveillance enhance the monitoring capacity. In surveillance, the collection of data for long...     

A Stable Low Power Dissipating 9 T SRAM for Implementation of 4 × 4 Memory Array with High Frequency Analysis

Wireless Personal Communications - Today’s high speed data processing and memory storage operations demand immediate data write and retrieval to meet up to benchmark. To act as a volatile or...     

Online Learning Model for Handling Different Concept Drifts Using Diverse Ensemble Classifiers on Evolving Data Streams

Abstract

The rapid growth of the information technology accelerates organizations to generate vast volumes of high-velocity data streams. The concept drift is a crucial issue, and discovering the sequential patterns over data streams are more challenging. The ensemble classifiers incrementally learn the data for providing quick reaction to the concept drifts. The ensemble classifiers have to process both the gradual and sudden concept drifts that happen in the real-time data streams. Thus, a novel ensemble classifier is essential that significantly reacting to various types of concept drifts quickly and maintaining the classification accuracy. This work proposes the stream data mining on the fly using an adaptive online learning rule (SOAR) model to handle both the gradual and sudden pattern changes and improves mining accuracy. Adding the number of classifiers fails because the ensemble tends to include redundant classifiers instead of high-quality ones. Thus, the SOAR includes different diversity levels of classifiers in the ensemble to provide fast recovery from both the concept drifts. Moreover, the SOAR synthesizes the essential features of the block and online-based ensemble and updates the weight of each classifier, regarding its quality. It facilitates adaptive windowing to handle both gradual and sudden concept drifts. To reduce the computational cost and analyze the data stream quickly, the SOAR caches the occurred primitive patterns into a bitmap with the internal relationship. Finally, the experimental results show that the SOAR performs better classification and accuracy over data streams.     

A Fast and Effective Pyridine-Free Method for the Determination of Hydroxyl Value of Hydroxyl-Terminated Polybutadiene and Other Hydroxy Compounds

Hydroxyl-terminated polybutadiene (HTPB) is the workhorse propellant binder for launch vehicle and missile applications. Accurate determination of the hydroxyl value (OHV) of HTPB is crucial for tailoring the ultimate mechanical and ballistic properties of the propellant derived. This article describes a fast and effective methodology free of pyridine based on acetic anhydride, N-methyl imidazole, and toluene for the determination of OHV of nonpolar polymers like HTPB and other hydroxyl compounds. This method gives accurate and reproducible results comparable to standard methods and is superior to existing methods in terms of user friendliness, efficiency, and time requirement.     

Theoretical Evaluation of Crosslink Density of Chain Extended Polyurethane Networks Based on Hydroxyl Terminated Polybutadiene and Butanediol and Comparison with Experimental Data

Polyurethane networks between hydroxyl terminated polybutadiene (HTPB) and butanediol (BD) were prepared using toluene diisocyanate (TDI) as the curative. HTPB and BD were taken at equivalent ratios viz.: 1:0, 1:1, 1:2, 1:4, and 1:8. Crosslink density (CLD) was theoretically calculated using α-model equations developed by Marsh. CLD for the polyurethane networks was experimentally evaluated from equilibrium swell and stress–strain data. Young’s modulus and Mooney–Rivlin approaches were adopted to calculate CLD from stress–strain data. Experimentally obtained CLD values were enormously higher than theoretical values especially at higher BD/HTPB equivalent ratios. The difference in the theoretical and experimental values for CLD was explained in terms of local crystallization due to the formation of hard segments and hydrogen bonded interactions.     

Effect of organically modified montmorillonite clay on the properties of hydroxyl terminated polydimethyl siloxane

Hydroxyl-terminated poly(dimethylsiloxane) cured by a mixture of methyl tris (methyl ethyl ketoxime) silane and 3-aminopropyl triethoxy silane system is known for satisfactory mechanical properties and chemical resistance. The effect of nanoclay on this poly(dimethyl siloxane) (PDMS) system is explored in this study. Organically modified clay (montmorillonite) nanocomposites of PDMS were processed by solution blending followed by cross linking. The effect of nanoclay content on the mechanical, barrier, thermal and dynamic mechanical properties of the nanocomposites were investigated in detail. X-ray diffraction studies reveal exfoliated nature of the nanoclay layers in the composites. The mechanical properties, such as tensile strength and elongation at break of PDMS, improved substantially on reinforcement with nanoclay. The maximum enhancement in properties occurred at a nanoclay content of 2-3%. Cross-link density increased with increase in nanoclay concentration up to 3% and decreased with further addition. The barrier properties were not significantly altered by the incorporation of nanoclay. Initial decomposition temperatures marginally increased at lower loading levels of nanoclay, whereas a reverse trend is observed at higher loadings. The glass transition temperature remains practically the same for all the compositions. The study demonstrates that nanoclay addition is an effective method for improving the properties of PDMS.     

"Normal'' P300 amplitude predicts rapid response to ECT in melancholia

Migraine aura without headache (acephalgic migraines) is a recognized subset of migrainous phenomena in the adult population. No reports of its prevalence or characteristics in a series of children exists. Using diagnostic criteria for migraine aura without headache established by the International Headache Society, a retrospective review of a computerized database of all patients referred over a 4-year period (July 1991 to June 1995 inclusive) to a single university-based pediatric neurologist was performed. Fourteen patients were identified, representing 2% of all patients with a primary diagnosis of migraine. Nine were females and 13 had a strong family history of migraines. Age of onset of symptoms ranged from 5 to 12 years with a mean of 8 years. Symptoms were episodic in all, varying in frequency from weekly to more typically monthly, lasting generally less than 10 min. In 9 patients the aura described was that of often colorful photopsias or scintillating scotomas. Two had micropsia, one had temporal distortion (time "speeded up"), one had hyperacusis, and the final patient had a vague sense of disconnection from her surroundings. Only 2 patients had a headache occasionally associated with the described aura. In addition to the acephalgic migraines, 9 patients had either common or classical migraines, the latter typically featuring aura distinct from those observed in these patients' acephalgic episodes. Neurologic examination, electrophysiologic investigation (EEG/evoked potentials), and neuroimaging were noncontributory in all instances. Migraine aura without headache is a recognizable benign migraine syndrome of late childhood.