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991.
Chattopadhyay S. Adhikari S. Sengupta S. Pal M. 《Very Large Scale Integration (VLSI) Systems, IEEE Transactions on》2000,8(6):724-735
This paper enumerates a new approach to the solution of classification problems based on the properties of Additive Cellular Automata. Classification problem plays a major role in various fields of computer science, such as grouping of the records in database systems, detection of faults in VLSI circuits, image processing, and so on. The state-transition graph of Non-group Cellular Automata (CA) consists of a set of disjoint trees rooted at some cyclic states of unit cycle length - thus forming a natural classifier. First a scheme of classifying the patterns distributed into only two classes has been dealt with. This has been further extended for solution of the multiclass classification problem. The Multiclass Classifier saves on an average 34% of memory as compared to the straight-forward approach storing directly the class of each pattern. A regular, modular, and cascadable hardware implementation of the classifier has been presented which is highly suitable for VLSI realization. The design has been specified in Verilog and verified for functional correctness 相似文献
992.
J. W. Kooi J. Kawamura J. Chen G. Chattopadhyay J. R. Pardo J. Zmuidzinas T. G. Phillips B. Bumble J. Stern H. G. LeDuc 《Journal of Infrared, Millimeter and Terahertz Waves》2000,21(9):1357-1373
We have developed a niobium titanium nitride (NbTiN) based superconductor-insulator-superconductor (SIS) receiver to cover the 350 micron atmospheric window. This frequency band lies entirely above the energy gap of niobium (700 GHz), a commonly used SIS superconductor. The instrument uses an open structure twin-slot SIS mixer that consists of two Nb/AlN/NbTiN tunnel junctions, NbTiN thin-film microstrip tuning elements, and a NbTiN ground plane. The optical configuration is very similar to the 850 GHz waveguide receiver that was installed at the Caltech Submillimeter Observatory (CSO) in 1997. To minimize front-end loss, we employed reflecting optics and a cooled beamsplitter at 4 K. The instrument has an uncorrected receiver noise temperature of 205K DSB at 800 GHz and 410K DSB at 900 GHz. The degradation in receiver sensitivity with frequency is primarily due to an increase in the mixer conversion loss, which is attributed to the mismatch between the SIS junction and the twin-slot antenna impedance. The overall system performance has been confirmed through its use at the telescope to detect a wealth of new spectroscopic lines. 相似文献
993.
Ogrin D Chattopadhyay J Sadana AK Billups WE Barron AR 《Journal of the American Chemical Society》2006,128(35):11322-11323
Epoxidation of single-walled carbon nanotubes (SWNTs) may be carried out by the reaction of SWNTs with either trifluorodimethyldioxirane or 3-chloroperoxybenzoic acid; the resulting O-SWNTs are spectroscopically similar to those formed by ozonolysis. Quantification of the epoxide substituents is possible through the catalytic de-epoxidation reaction using MeReO3/PPh3 and the 31P NMR spectroscopy. The de-epoxidation methodology may be used to determine that wet air oxidation is preferable to either acid or O2/SF6 purification. We have demonstrated that previously assumed "pure" SWNTs are actually "doped" to a level of at least 1 oxygen per 250 carbon atoms. 相似文献
994.
Euler-Euler two-fluid model is used to simulate the hydrodynamics of gas-solid flow in a bubbling flu- idized bed with Geldert B particles where the solid property is calculated by applying the kinetic theory of granular flow (KTGF). Johnson and Jackson wall boundary condition is used for the particle phase, and different amount of slip between particle and wall is given by varying the specularity coefficient (φ) from 0 to 1. The simulated particle velocity, granular temperature and particle volume fraction are compared to investigate the effect of different wall boundary conditions on the hydrodynamic behavior, Some of the results are also compared with the available experimental data from the literature. It was found that the model predictions are sensitive to the specularity coefficient. The hydrodynamic behavior deviated sig- nificantly for φ = 0 and φ = 0.01 with maximum deviation found at φ = 0 i.e. free-slip condition. However, the overall bed height predicted by all the conditions is similar. 相似文献
995.
The objective of this paper is to discuss the Chameleon Brans–Dicke gravity with non-minimally matter coupling of scalar field. We take modified Holographic Ricci dark energy model in this gravity with its energy density in interaction with energy density of cold dark matter. We assume power-law ansatz for scale factor and scalar field to discuss potential as well as coupling functions in the evolving universe. These reconstructed functions are plotted versus scalar field and time for different values of power component of scale factor n. We observe that potential and coupling functions represent increasing behavior, in particular, consistent results for a specific value of n. Finally, we have examined validity of the generalized second law of thermodynamics and we have observed its validity for all values of n. 相似文献
996.
Santanu Biswas Sourav Kumar Sasmal Sudip Samanta Md. Saifuddin Nikhil Pal Joydev Chattopadhyay 《Nonlinear dynamics》2017,87(3):1553-1573
In this article, an eco-epidemiological system with weak Allee effect and harvesting in prey population is discussed by a system of delay differential equations. The delay parameter regarding the time lag corresponds to the predator gestation period. Mathematical features such as uniform persistence, permanence, stability, Hopf bifurcation at the interior equilibrium point of the system is analyzed and verified by numerical simulations. Bistability between different equilibrium points is properly discussed. The chaotic behaviors of the system are recognized through bifurcation diagram, Poincare section and maximum Lyapunov exponent. Our simulation results suggest that for increasing the delay parameter, the system undergoes chaotic oscillation via period doubling. We also observe a quasi-periodicity route to chaos and complex dynamics with respect to Allee parameter; such behavior can be subdued by the strength of the Allee effect and harvesting effort through period-halving bifurcation. To find out the optimal harvesting policy for the time delay model, we consider the profit earned by harvesting of both the prey populations. The effect of Allee and gestation delay on optimal harvesting policy is also discussed. 相似文献
997.
Naskar S Mishra D Chattopadhyay SK Corbella M Blake AJ 《Dalton transactions (Cambridge, England : 2003)》2005,(14):2428-2435
Five seven- or eight-coordinate manganese complexes of hydrazone ligands have been prepared. Three seven-coordinate neutral Mn(II) complexes: [Mn(dapA2)]n (1), [Mn(dapB2)(H2O)2] (2), [Mn(dapS2)(H2O)2] (3) have been synthesized from the bis-Schiff bases of 2,6-diacetylpyridine: dap(AH)2, dap(BH)2 and dap(SH)2 (AH = anthraniloyl hydrazide, BH = benzoyl hydrazide, SH = salicyloyl hydrazide), respectively. Two eight-coordinate Mn(II) complexes: [Mn(dapS)2] (4) and [Mn(dapB)2].3H2O (5) have been synthesized from the mono-Schiff bases dapBH and dapSH, respectively. The complexes have been characterized by elemental analyses and by IR, UV-Vis., FAB mass, EI mass and EPR spectroscopy. The molecular structures of 1, 3.DMF and 4.DMF have been determined by single-crystal X-ray diffraction. The mono-Schiff bases are monoanionic and the bis-Schiff bases are dianionic. The octa-coordinated mono-Schiff base complex 4 adopts a dodecahedral geometry, while the hepta-coordinated bis-Schiff base complex 1 forms a one-dimensional linear polymeric chain. A weak antiferromagnetic exchange interaction (J=-0.15 cm(-1)) between the Mn(II) ions in is attributed to weak Mn...Mn interaction through the PhNH(2) moiety of the ligand, as indicated by extended-Hückel molecular orbital calculations. A good simulation of the EPR spectrum of a frozen solution (DMSO at 4 K) of compound 1 was obtained with g=2.0, D=0.1 cm(-1), E=0.01 cm(-1). The EPR spectrum of a powdered sample of compound 1 shows a large broadening of the signal, due in part, to the important zero-field splitting of the hepta-coordinated Mn(II) ion. 相似文献
998.
Adler C Ahammed Z Allgower C Amonett J Anderson BD Anderson M Averichev GS Balewski J Barannikova O Barnby LS Baudot J Bekele S Belaga VV Bellwied R Berger J Bichsel H Billmeier A Bland LC Blyth CO Bonner BE Boucham A Brandin A Bravar A Cadman RV Caines H Calderón de la Barca Sánchez M Cardenas A Carroll J Castillo J Castro M Cebra D Chaloupka P Chattopadhyay S Chen Y Chernenko SP Cherney M Chikanian A Choi B Christie W Coffin JP Cormier TM Cramer JG Crawford HJ Deng WS Derevschikov AA 《Physical review letters》2002,89(20):202301
Inclusive transverse momentum distributions of charged hadrons within 0.2
相似文献
999.
A.K. Chattopadhyay 《The European Physical Journal B - Condensed Matter and Complex Systems》2002,29(4):567-576
We study the dynamics of a growing crystalline facet where the growth mechanism is controlled by the geometry of the local
curvature. A continuum model, in (2+1) dimensions, is developed in analogy with the Kardar-Parisi-Zhang (KPZ) model is considered
for the purpose. Following standard coarse graining procedures, it is shown that in the large time, long distance limit, the
continuum model predicts a curvature independent KPZ phase, thereby suppressing all explicit effects of curvature and local
pinning in the system, in the “perturbative” limit. A direct numerical integration of this growth equation, in 1+1 dimensions,
supports this observation below a critical parametric range, above which generic instabilities, in the form of isolated pillared
structures lead to deviations from standard scaling behaviour. Possibilities of controlling this instability by introducing
statistically “irrelevant" (in the sense of renormalisation groups) higher ordered nonlinearities have also been discussed.
Received 23 April 2002 / Received in final form 24 July 2002 Published online 31 October 2002
RID="a"
ID="a"e-mail: akc@mpipks-dresden.mpg.de 相似文献
1000.
The tip morphology in the nanoscale is discussed as a member of the one-dimensional nanostructure family. Different growth techniques used for the synthesis of the nanotips have been outlined and compared against each other including, etching, pyrolysis, physical, and chemical vapour deposition. Growth models for hollow and solid nanotips are compared and discussed in detail with a thrust on the ‘cone-helix’ model for the hollow tips and the ‘platelet stacking’ model for the solid tips. Application of the nanotips in field emission, scanning probe microscopy, sensing, anti-reflection, and nanoindentation is discussed. 相似文献