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991.
Manojit Chattopadhyay Surajit Chattopadhyay Pranab K. Dan 《The International Journal of Advanced Manufacturing Technology》2011,52(9-12):1019-1030
Machine?Cpart cell formation is used in cellular manufacturing in order to process large varieties, improve quality, and lower work-in-process levels, reducing manufacturing lead time and customer response time while retaining flexibility for new products. This paper presents a new and novel approach for obtaining machine cells and part families. In cellular manufacturing, the fundamental problem is the formation of part families and machine cells. The present paper deals with the self-organizing map (SOM) method, an unsupervised learning algorithm in artificial intelligence which has been used as a visually decipherable clustering tool of machine?Cpart cell formation. The objective of the paper is to cluster the binary machine?Cpart matrix through visually decipherable cluster of SOM color coding and labeling via the SOM map nodes in such a way that the part families are processed in that machine cell. The U-matrix, component plane, principal component projection, scatter plot, and histogram of SOM have been reported in the present work for the successful visualization of the machine?Cpart cell formation. Computational result with the proposed algorithm on a set of group technology problems available in the literature is also presented. The proposed SOM approach produced solutions with a grouping efficacy that is at least as good as any results earlier reported in the literature and improved the grouping efficacy for 70% of the problems and was found to be immensely useful to both industry practitioners and researchers. 相似文献
992.
R. Sathyamoorthy S. Senthilarasu S. Lalitha A. Subbarayan K. Natarajan Xavier Mathew 《Solar Energy Materials & Solar Cells》2004,82(1-2):169
Solar energy as the principle source has become very attractive, as it is abundantly available, can be tapped locally, pollution free and commercially viable over a period. Solar energy may be converted to other forms of higher-grade energy through one of several methods such as photothermal, photochemical, photoelectrochemical and photovoltaic (PV). Among these, as noted above the cleanest and most direct and efficient and of converts to electrical power is with the help of PV or solar cell devices. Photovoltaics are one of the hottest areas of research today. Nowadays organic material finds greater importance in the PV cell fabrications. Among the available organic materials ZincPhthalocyanine is a promising candidate for the solar cell applications, because of its easy synthesization and non-toxic to the environment. The major part of incident light in the visible region effectively contributes to photocarrier generation and the excited ZnPc molecules play an important role in PV effect. In this paper, we have reported electrical transport properties of flash evaporated ZincPhthalocyanine thin films have been reported. DC conduction mechanism in these films (Al–ZnPc–Al structure) was studied at different temperatures. The field dependence behaviour on activation energy and possible conduction mechanism in the ZnPc films under DC field has been discussed. 相似文献
993.
S. Lalitha R. Sathyamoorthy S. Senthilarasu A. Subbarayan K. Natarajan 《Solar Energy Materials & Solar Cells》2004,82(1-2):187
The X-ray diffraction analysis of vacuum-evaporated cadmium telluride (CdTe) films reveals that the structure of the films is polycrystalline in nature for the samples prepared at higher substrate temperatures. The crystallite size (D), dislocation density (δ) and strain () were calculated. The composition analysis was made by the energy dispersive X-ray analysis. It confirmed the equal distribution of Cd and Te elements in the CdTe films. The fundamental optical parameters like band gap and extinction coefficient are calculated from the transmission spectra. The possible optical transition in these films is found to be direct and allowed. The charge transport phenomenon appears to be space charge limited conduction. Various electrical parameters were determined from the I–V analysis. 相似文献
994.
Pinaki Das GuptaSaikat Chattopadhyay R.J. ChoudharyD.M. Phase Pratima Sen 《Materials Letters》2011,65(13):2073-2075
Zn0.965Cd0.035O/ZnO bilayer film has been developed using pulsed laser deposition (PLD) technique. The film is characterized by X-ray diffraction (XRD), energy dispersion analysis by X-ray (EDAX), UV-Vis and Valence band spectra (VBS). The XRD pattern confirms the single phase crystalline nature of the deposited film. The UV-Vis spectra establish a reduction of band gap (≈ 340 meV) in the ternary alloy film of Zn0.965Cd0.035O/ZnO. The VBS shows shift in the peak corresponding to nonbonding oxygen p states. We also obtained valence band offset of 191 meV in the film showing the rise of valence band. The calculated conduction band offset is found to be −51 meV which confirms the lowering of the conduction band in the ternary alloy film. 相似文献
995.
D. Roy A. SinhaP.P. Chattopadhyay I. Manna 《Materials Science and Engineering: A》2011,528(28):8047-8050
Present study concerns assessment of nanomechanical property in the bulk Al65Cu20Ti15 alloy with varying microstructure synthesized by consolidation of mechanically alloyed powder at different temperature. The microstructure after consolidation at room temperature and 500 °C exhibits completely amorphous and nanocrystalline states respectively. Nanoindentation experiments suggest that the maximum strength and hardness values are achieved in the sample sintered at 450 °C. The corresponding microstructure revealed dispersion of nanocrystalline intermetallic phase (<50 nm) in the amorphous matrix. 相似文献
996.
Chattopadhyay T 《Applied optics》2011,50(32):6049-6056
Logic units are the building blocks of many important computational operations likes arithmetic, multiplexer-demultiplexer, radix conversion, parity checker cum generator, etc. Multifunctional logic operation is very much essential in this respect. Here a programmable Boolean logic unit is proposed that can perform 16 Boolean logical operations from a single optical input according to the programming input without changing the circuit design. This circuit has two outputs. One output is complementary to the other. Hence no loss of data can occur. The circuit is basically designed by a 2×2 polarization independent optical cross bar switch. Performance of the proposed circuit has been achieved by doing numerical simulations. The binary logical states (0,1) are represented by the absence of light (null) and presence of light, respectively. 相似文献
997.
Sandip MondalTanmay Chattopadhyay Swarup Kumar NeogiTotan Ghosh Aritra BanerjeeDebasis Das 《Materials Letters》2011,65(4):783-785
A coordination polymer, Na2Cd2I6L2(H2O)6 [L = Urotropine] has been employed as sole precursor to synthesize CdO particles. Two different preparation methods viz (i) pyrolysis of the title compound at 700 °C for 2 h and (ii) forming cadmium hydroxide from the title compound followed by pyrolysis at 700 °C for 2 h have been used for the synthesis of nano sized CdO-I and CdO-II, respectively. From powder XRD data the lattice parameters (0.4701 and 0.4696 nm respectively for the two samples) and particle size (~ 77 and 30 nm for CdO-I and CdO-II) have been evaluated. Morphology of the two varieties of CdO is widely different as is evident from their SEM images. The estimated values of the band gap of 2.53 eV and 2.59 eV for CdO-I and CdO-II respectively are obtained from the optical spectral analysis. 相似文献
998.
Manangi Chamaraja Jayaprakash Kora Revanna Lalitha Konduru Sarada Deshmukh Ashok Reddy Arasaiah Arasaiah 《亚洲传热研究》2022,51(2):1809-1829
The properties of ferromagnetic fluids make them suitable for a wide range of applications, including loudspeakers, magnetic resonance imaging, computer hard drives, magnetic drug delivery, and magnetic hyperthermia. Owing to all such potential applications, the present research work is established to explain the stagnation point flow, heat, and mass transfer of Walters-B liquid in the presence of magnetic dipole, Brownian diffusion, and thermophoresis. To control the nanoparticles concentration at the surface, a passive control condition is employed. Using suitable similarity transformations, the governing equations are converted into nonlinear ordinary differential equations. Noticeable behavior of significant parameters on flow fields is studied graphically. The significant outcomes of the present study are that the increased values of viscoelastic parameter decline the velocity but an inverse trend is seen in heat transfer. The increased values of the Brownian motion parameter decline the heat transfer but a contrary trend is seen for augmented values of the thermophoresis parameter. The heat transfer rate is increased for rising values of radiation parameter and Biot number. The upward values of the thermophoresis parameter decline the rate of mass transfer. The escalating values of ferromagnetic interaction and velocity ratio parameters improve the skin friction. 相似文献
999.
Jayanta Kumar Rakshit Jitendra Nath Roy Tanay Chattopadhyay 《Journal of Computational Electronics》2014,13(1):278-286
In this paper, a simple but novel scheme for all optical clocked D flip flop based on single micro-ring resonator with a feedback loop is proposed and prescribed. The GaAs-AlGaAs based micro-ring resonator is modulated through optical pump beam. The proposed clocked D flip flop presents two stable states determined by the phase shift in the ring and will allow synchronization of different optical devices by clock pulse (optical control pump beam). Theoretical model of clocked D flip flop has been developed using single micro-ring resonator and numerical simulation results confirming described methods are given in this paper. The design will be helpful in designing all optical integrated circuit. 相似文献
1000.
W. D. Duncan R. E. Schwall K. D. Irwin J. A. Beall C. D. Reintsema William Doriese Hsiao-Mei Cho Brian Estey Goutam Chattopadhyay Peter Ade Carole Tucker 《Journal of Low Temperature Physics》2008,151(3-4):777-783
We present the outline of the optical design of a TeraHertz (THz) imager for the detection of shrapnel-loaded improvised explosive
devices (IED) devices at “stand-off” distances of 14–26 meters. The system will use 4 antenna-coupled TES detector arrays
of 16 by 16 pixels cooled in a cryogen-free system with microwave readout to see beneath clothing at non-lethal detonation
distances. A spatial resolution of ∼10 mm and close to video frame rates is anticipated.
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