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131.
Gonzalez A.F. Bhattacharya M. Kulkarni S. Mazumder P. 《Solid-State Circuits, IEEE Journal of》2001,36(6):924-932
This paper presents a fully integrated implementation of a multivalued-logic signed-digit full adder (SDFA) circuit using a standard 0.6-μm CMOS process. The radix-2 SDFA circuit, based on two-peak negative-differentiaI-resistance (NDR) devices, has been implemented using MOS-NDR, a new prototyping technique for circuits that combine MOS transistors and NDR devices. In MOS-NDR, the folded current-voltage characteristics of NDR devices such as resonant-tunneling diodes (RTDs) are emulated using only nMOS transistors. The SDFA prototype has been fabricated and correct function has been verified. With an area of 123.75 by 38.7 μm2 and a simulated propagation delay of 17 ns, the MOS-NDR prototype is more than 15 times smaller and slightly faster than the equivalent hybrid RTD-CMOS implementation 相似文献
132.
Rachana Ranu Yatishwar Chauhan Amar Ratan Pramod K. Singh Bhaskar Bhattacharya Sandeep K. Tomar 《IET nanobiotechnology / IET》2019,13(4):363
Nanomaterials synthesis using natural sources is the technology to up come with advanced materials through extracts of plant, microorganisms, poultry waste etc. In this study, the authors report the synthesis of porous carbon nanotubes using high‐temperature decomposition technique facilitated by cobalt salt using chicken fats, a poultry waste as a precursor. Since chicken fats contain fatty acids which can decompose into short hydrocarbon chains and cobalt can act as the catalyst. The formation of carbon nanotubes was confirmed by Raman spectra, peaks at 1580 and 1350.46 cm−1 confirmed the graphite mode G‐band and structural imperfections defect mode D‐band, respectively. Transmission electron microscopy showed the formation of tube‐like structures. Nitrogen adsorption–desorption studies showed the high‐surface area of 418.1 m2 g−1 with an estimated pore diameter of 8.1 nm. Thermogravimetry analysis–derivative thermogravimetric analysis–differential thermal analysis showed the instant weight loss at 517°C attributed to the rapid combustion of nanotubes. A vibrating‐sample magnetometer showed the paramagnetic nature of the so‐formed carbon nanotubes formed.Inspec keywords: transmission electron microscopy, infrared spectra, nanomagnetics, pyrolysis, decomposition, adsorption, desorption, carbon nanotubes, differential thermal analysis, thermal analysis, nanofabrication, Raman spectra, X‐ray diffraction, scanning electron microscopy, paramagnetic materialsOther keywords: biogenic synthesis, highly porous carbon nanotubes, microorganisms, high‐temperature decomposition technique, cobalt salt, chicken fats, fatty acids, short hydrocarbon chains, Raman spectra, graphite mode G‐band, structural imperfections defect mode D‐band, transmission electron microscopy, paramagnetic nature, thermo‐magnetic properties, poultry waste, nitrogen adsorption‐desorption studies, thermogravimetry analysis, differential thermal analysis, carbon nanotubes, temperature 517.0 degC, C 相似文献
133.
C. B. Samantaray A. Dhar D. Bhattacharya M. L. Mukherjee S. K. Ray 《Journal of Materials Science: Materials in Electronics》2001,12(7):365-370
The effect of post-deposition annealing on the structural and optical properties of barium strontium titanate, Ba0.8Sr0.2TiO3 film has been investigated. The films have been deposited on oxidized p-silicon substrates by r.f. magnetron sputtering followed by annealing in O2 atmosphere at different temperatures. In situ deposition has also been carried out at 550 °C for comparison. The nature of the variation of refractive index and extinction coefficient with annealing temperature and wavelength has been studied. Absorption band edges shift towards lower photon energy values as the temperature is increased causing a reduction in the optical band gap energy. Infrared absorption bands show a cubic symmetry at lower frequency and are found to be broadened and even split at higher frequency. 相似文献
134.
Wei Dong Zhou Sabarinathan J. Bhattacharya P. Kochman B. Berg E.W. Pei-Chen Yu Pang S.W. 《Quantum Electronics, IEEE Journal of》2001,37(9):1153-1160
A microcavity surface-emitting coherent electroluminescent device operating at room temperature under pulsed current injection is described. The microcavity is formed by a single defect in the center of a 2-D photonic crystal consisting of a GaAs-based heterostructure. The gain region consists of two 70-Å compressively strained In0.15Ga0.85As quantum wells, which exhibit a spontaneous emission peak at 940 nm. The maximum measured output power from a single device is 14.4 μW. The near-field image of the output resembles the calculated TE mode distribution in a single defect microcavity. The measured far-field pattern indicates the predicted directionality of a microcavity light source. The light-current characteristics of the device exhibit a gradual turn-on, or a soft threshold, typical of single- or few-mode microcavity devices. Analysis of the characteristics with the carrier and photon rate equations yields a spontaneous emission factor β≈0.06 相似文献
135.
Zhenqiang Ma Bhattacharya P. Jae-Sung Rieh Ponchak G.E. Alterovitz S.A. Croke E.T. 《Microwave and Wireless Components Letters, IEEE》2001,11(10):401-403
The degradation behavior of NPN Si/SiGe/Si heterojunction bipolar transistors, grown by solid-source molecular beam epitaxy (MBE), has been studied by accelerated lifetime testing at different ambient temperatures. The degradations of the dc current gain and the microwave performance of the devices are explained in terms of recombination enhanced impurity diffusion (REID) of boron atoms from the base region and the subsequent formation of parasitic energy barriers at the base-emitter and base-collector junctions 相似文献
136.
Parameterized dataflow modeling for DSP systems 总被引:1,自引:0,他引:1
Dataflow has proven to be an attractive computation model for programming digital signal processing (DSP) applications. A restricted version of dataflow, termed synchronous dataflow (SDF), that offers strong compile-time predictability properties, but has limited expressive power, has been studied extensively in the DSP context. Many extensions to synchronous dataflow have been proposed to increase its expressivity while maintaining its compile-time predictability properties as much as possible. We proposed a parameterized dataflow framework that can be applied as a meta-modeling technique to significantly improve the expressive power of any dataflow model that possesses a well-defined concept of a graph iteration, Indeed, the parameterized dataflow framework is compatible with many of the existing dataflow models for DSP including SDF, cyclo-static dataflow, scalable synchronous dataflow, and Boolean dataflow. In this paper, we develop precise, formal semantics for parameterized synchronous dataflow (PSDF)-the application of our parameterized modeling framework to SDF-that allows data-dependent, dynamic DSP systems to be modeled in a natural and intuitive fashion. Through our development of PSDF, we demonstrate that desirable properties of a DSP modeling environment such as dynamic reconfigurability and design reuse emerge as inherent characteristics of our parameterized framework. An example of a speech compression application is used to illustrate the efficacy of the PSDF approach and its amenability to efficient software synthesis techniques. In addition, we illustrate the generality of our parameterized framework by discussing its application to cyclo-static dataflow, which is a popular alternative to the SDF model 相似文献
137.
Bhattacharya D. Pillai S.R. Antoniou A. 《Geoscience and Remote Sensing, IEEE Transactions on》1997,35(3):699-707
Two different neural network schemes for the classification of light detection and ranging (LIDAR) waveforms for the LARSEN 500 airborne system and for extraction of ocean information are proposed. The first method employs a single layer of linear neurons for classification of waveforms into various clusters. Both unsupervised and supervised learning algorithms have been employed to demonstrate the spatial distribution of milt in near-shore waters. In the second method, a new multistage multilayer feedforward architecture is used for the classification of the waveforms and for the extraction of various types of ocean information. The stage I networks work in a parallel fashion and map the input waveforms to a set of characteristics. The networks in stage II use these characteristics to assign a signature number to the waveform or extract other information. Both the schemes are used with real-world data collected by the LARSEN 500 system. The paper concludes with experimental results and comparisons 相似文献
138.
When making decisions we need to consider the possible alternatives and then choose the optimal alternative. The uncertainty of subjective judgment is present during this selection process. Also, decision making becomes difficult when the available information is incomplete or imprecise. This kind of problem exists while selecting a project. There are also several critical factors that are involved in the selection process, including market conditions, availability of raw materials, etc. The decision mechanism is constrained by the uncertainty inherent in the determination of the relative importance of each attribute element. In this paper, me develop a system for the project selection using fuzzy logic. Fuzzy logic enables us to emulate the human reasoning process and make decisions based on vague or imprecise data. Our approach is based on uncertainty reduction. The optimal alternative is formed by the relative weights of each attribute's elements combined over all the attribute membership functions. We also do a case study for the selection of software packages. Our system could be easily applied to other project selection problems under uncertainty 相似文献
139.
A new hierarchical modeling and test generation technique for digital circuits is presented. First, a high-level circuit model and a bus fault model are introduced—these generalize the classical gate-level circuit model and the single-stuck-line (SSL) fault model. Faults are represented by vectors allowing many faults to be implicitly tested in parallel. This is illustrated in detail for the special case of array circuits using a new high-level representation, called the modified pseudo-sequential model, which allows simultaneous test generation for faults on individual lines of a multiline bus. A test generation algorithm called VPODEM is then developed to generate tests for bus faults in high-level models of arbitrary combinational circuits. VPODEM reduces to standard PODEM if gate-level circuit and fault models are used. This method can be used to generate tests for general circuits in a hierarchical fashion, with both high- and low-level fault types, yielding 100 percent SSL fault coverage with significantly fewer test patterns and less test generation effort than conventional one-level approaches. Experimental results are presented for representative circuits to compare VPODEM to standard PODEM and to random test generation techniques, demonstrating the advantages of the proposed hierarchical approach. 相似文献
140.
A.K. Bhattacharya R.R.P. Chaudhary R.R.S. Rathore 《Journal of Stored Products Research》1976,12(3):143-148
Ephestia cautella (Walker) was reared on 39 varieties of soybean at 30 ± 1°C, 80 ± 5% r.h. and 12 hr light: 12 hr dark photoperiod. Larvae were reared individually on whole grains and flours of each variety and larval period, pupal period, per cent pupation and per cent adult formation were recorded. Larvae failed to develop on grains of 13 varieties while grains of Grant, Clark glabrous, Clark dense, Henry, Harrowmanchu and Hawkey-63 were highly susceptible to this pest. On the other hand larvae completed development successfully on all 39 varieties when seeds were ground into flours. It was also clear that UPSM-158 was somewhat tolerant to the attack of this pest while UPSM-120, Hawkey-63, Clark-63, Chippewa, UPSM-57, Harrowmanchu, Hampton, Goldsoy, Davis, Hood, and Kohachugatsu were also less efficient in supporting the development. Addition of 5% yeast to these varieties produced remarkable improvement in the quality of the diet which indicated that the flours of these varieties were deficient in one or more essential nutrients. 相似文献