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41.
BV Reddy S Jalal P Borkar JS Yadav PP Reddy AC Kunwar B Sridhar 《Organic & biomolecular chemistry》2012,10(32):6562-6568
A novel intramolecular Prins cyclization of (Z)-2-(5-hydroxypent-2-enyl)phenol with various aldehydes has been achieved using 10 mol% In(OTf)(3) and 30 mol% TsOH to produce the cis-fused hexahydropyrano[4,3-b]chromene derivatives in good yields, while the coupling of (E)-2-(5-hydroxypent-2-enyl)phenol with aldehydes under similar conditions affords the corresponding trans-fused hexahydropyrano[4,3-b]chromene derivatives. 相似文献
42.
Stability and convergence properties of stochastic approximation algorithms are analyzed when the noise includes a long range dependent component (modeled by a fractional Brownian motion) and a heavy tailed component (modeled by a symmetric stable process), in addition to the usual ‘martingale noise’. This is motivated by the emergent applications in communications. The proofs are based on comparing suitably interpolated iterates with a limiting ordinary differential equation. Related issues such as asynchronous implementations, Markov noise, etc. are briefly discussed. 相似文献
43.
The brain is believed to be particularly vulnerable to arsenic due to its high oxygen consumption rate and high level of polyunsaturated fatty acids and relatively high rate of oxygen free radical generate without commensurable level of arsenic. Hence, in the present work an attempt is made to study the changes in the biochemical contents in the brain tissues of edible fish Labeo rohita due to arsenic intoxication using Fourier Transform Infrared (FT-IR) spectroscopy. FT-IR spectra reveal significant differences in absorbance intensities between the control and arsenic intoxicated brain tissues, reflecting an alteration on the major biochemical constituents, such as lipids, proteins and nucleic acids of the brain tissues of L. rohita due to arsenic intoxication. Further, the administration of antidote DMSA improves the protein and lipid contents significantly in the brain tissues when compared to arsenic intoxicated tissues. The decrease in α-helix structure due to arsenic intoxication might be responsible for the increase in β-sheet secondary structures, which is consistent with the mechanism of β-sheet formation. 相似文献
44.
V. S. Borkar 《Journal of Optimization Theory and Applications》1991,68(1):117-138
The self-tuning method of adaptive control for diffusions consists of estimating the unknown parameter on line and using its current estimate as the true parameter for the selection of the control at each time. The a.s. optimality of this scheme for the ergodic or long-run average criterion can be established under an identifiability condition on the system, but may fail otherwise. We present a modified self-tuning scheme along the lines of the Kumar-Becker-Lin scheme for Markov chains and prove its a.s. optimality. Several heuristic issues related to this scheme are also discussed. 相似文献
45.
The self-tuning scheme for the adaptive control of a diffusion process is studied with long-run average cost criterion and maximum likelihood estimation of parameters. Asymptotic optimality under a suitable identifiability condition is established under two alternative sets of hypotheses—a Lyapunov-type stability criterion and a condition on cost which penalizes instability. 相似文献
46.
An error in the proof of Theorem 4.1 of Ref. 1 is corrected. 相似文献
47.
Pande S. S. Borkar S. P. Prafulla S. Srivastava V. D. Behare A. Mukhopadhyay P. K. Ghodgaonkar M. D. Kataria S. K. 《Pramana》2004,63(2):459-463
Linear position sensitive detectors (PSDs) are widely used to configure neutron diffractometers and other instruments. Necessary
front-end electronics and a data acquisition system [1] is developed to cater to such instruments built around the Dhruva
research reactor in BARC. These include three diffractometers with multiple PSDs and four with single PSD. The front-end electronics
consists of high voltage units, preamplifiers [2],shaping amplifiers, ratio ADCs (RDC) [3]. The data acquisition system consists
of an interface card and software. Commercially available hardware like temperature controller or stepper motor controller
connected over GPIB or RS232 are also integrated in the data acquisition system. The data acquisition is automated so that
it can continue unattended for control parameter like temperature, thus enabling optimum utilization of available beam time.
The instrumentation is scalable and can be easily configured for various instrumental requirements. The front-end electronics
and the data acquisition system are described here. 相似文献
48.
Vivek S. Borkar 《Applied Mathematics and Optimization》1988,18(1):67-83
This paper considers control of nondegenerate diffusions in a bounded domain with a cost associated with the boundary-crossings of a subdomain. Existence of optimal Markov controls and a verification theorem are established.Research supported by ARO Contract No. DAAG29-84-K-0005 and AFOSR 85-0227. 相似文献
49.
We consider a Robbins-Monro type iteration wherein noisy measurements are event-driven and therefore arrive asynchronously. We propose a modification of step-sizes that ensures desired asymptotic behaviour regardless of this aspect. This generalizes earlier results on asynchronous stochastic approximation wherein the asynchronous behaviour is across different components, but not along the same component of the vector iteration, as is the case considered here. 相似文献
50.