Analysis and simulation of substrate coupling in integrated circuits

A technique is presented which allows efficient calculation of substrate-coupling macromodels in integrated circuits. the technique can be used to calculate node-to-node resistances or impedances in substrate models. Examples of the technique applied to several test structures are presented.     

Morphology of EVA based nanocomposites under shear and extensional flow

Shear and extensional rheological measurements were conducted in conjunction with laser light scattering (LLS) on ethylene‐vinyl acetate copolymer (EVA) nanocomposites. The materials were prepared by melt‐mixing EVA and commercially acquired layered silicates. Wide Angle X‐Ray Scattering (WAXS) was used to ascertain the degree of layer swelling. This could be attributed to the intercalation of polymer chains into the interlayer of the silicates. The nanocomposites prepared were determined to be predominantly intercalated in nature. In shear rheological tests, the nanocomposites exhibited an increase in viscoelastic properties compared to the pure EVA. The extent of this property enhancement was not as pronounced as had been reported in many instances with respect to other polymer nanocomposites. This could be attributed to the absence of a network structure normally observed in an exfoliated system. The extensional rheological tests showed an increase in extensional flow properties. This was confirmed by the LLS, which indicated that the filled systems had higher deformability than the unfilled one. Polym. Eng. Sci. 44:1220–1230, 2004. © 2004 Society of Plastics Engineers.     

Molecular Sorption by Heterogeneous Natural Rubber/Poly(ethylene-co-vinyl acetate) Blend Systems

The sorption of n-alkanes, viz. hexane, heptane and octane by cross-linked natural rubber/poly(ethylene-co-vinyl acetate) (NR/EVA) blends has been studied at 28, 38, 48 and 58°C, with special reference to the effects of EVA content, cross-linking systems, penetrant nature and temperature. The solvent transport was found to decrease with increase in EVA content in the blends. The effects of blend ratio on the transport characteristics have been correlated with the phase morphology of the blends, using scanning electron micrographs and optical micrographs. Among the three vulcanising systems, viz. sulphur (S), dicumyl peroxide (DCP) and a mixed system (S + DCP) employed for the matrix, the DCP cross-linked blends exhibited the lowest solvent uptake. Octane has been found to show higher interaction with the blends than hexane and heptane, probably owing to the closer solubility parameter values. The computed transport coefficients, viz. diffusion coefficient and permeability coefficient, were found to decrease with increase in EVA content in the blends. At room temperature, the mechanism of diffusion was found to deviate slightly from the regular Fickian trend for all blend systems. The blend–solvent interaction parameter and the activation energy for transport were also determined from the sorption data.     

Cure characteristics,morphology, and mechanical properties of ethylene–propylene–diene–monomer rubber/acrylonitrile butadiene rubber blends

Blends based on ethylene–propylene–diene monomer rubber (EPDM) and acrylonitrile butadiene rubber (NBR) was prepared. Sulfur was used as the vulcanizing agent. The effects of blend ratio on the cure characteristics and mechanical properties, such as stress–strain behavior, tensile strength, elongation at break, hardness, rebound resilience, and abrasion resistance have been investigated. Tensile and tear strength showed synergism for the blend containing 30% of NBR, which has been explained in terms of morphology of the blends attested by scanning electron micrographs. A relatively cocontinuous morphology was observed for 70 : 30, EPDM/NBR blend system. The experimental results have been compared with the relevant theoretical models. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Design and implementation of a block‐backstepping based tracking control for nonholonomic wheeled mobile robot

This paper presents formulation of a novel block‐backstepping based control algorithm to overcome the challenges posed by the tracking and the stabilization problem for a differential drive wheeled mobile robot (WMR). At first, a two‐dimensional output vector for the WMR has been defined in such a manner that it would decouple the two control inputs and, thereby, allow the designer to formulate the control laws for the two inputs one at a time. Actually, the decoupling has been carried out in a way to convert the system into block‐strict feedback form. Thereafter, block‐backstepping control algorithm has been utilized to derive the expressions of the control inputs for the WMR system. The proposed block‐backstepping technique has further been enriched by incorporating an integral action for enhancing the steady state performance of the overall system. Global asymptotic stability of the overall system has been analyzed using Lyapunov stability criteria. Finally, the proposed control algorithm has been implemented on a laboratory scale differential drive WMR to verify the effectiveness of the proposed control law in real‐time environment. Indeed, the proposed design approach is novel in the sense that it has judiciously exploited the nonholonomic constraint of the WMR to result in a reduced order block‐backstepping controller for the WMR, and thereby, it has eventually yielded a compact expression of the control law that is amenable to real‐time implementation. Copyright © 2015 John Wiley & Sons, Ltd.     

Neutrosophic classifier: An extension of fuzzy classifer

Fuzzy classification has become of great interest because of its ability to utilize simple linguistically interpretable rules and has overcome the limitations of symbolic or crisp rule based classifiers. This paper introduces an extension to fuzzy classifier: a neutrosophic classifier, which would utilize neutrosophic logic for its working. Neutrosophic logic is a generalized logic that is capable of effectively handling indeterminacy, stochasticity acquisition errors that fuzzy logic cannot handle. The proposed neutrosophic classifier employs neutrosophic logic for its working and is an extension of commonly used fuzzy classifier. It is compared with the commonly used fuzzy classifiers on the following parameters: nature of membership functions, number of rules and indeterminacy in the results generated. It is proved in the paper that extended fuzzy classifier: neutrosophic classifier; optimizes the said parameters in comparison to the fuzzy counterpart. Finally the paper is concluded with justifying that neutrosophic logic though in its nascent stage still holds the potential to be experimented for further exploration in different domains.     

Stochastic and Dynamic Shipper Carrier Network Design Problem

The focus of this work is to determine the optimal storage capacity to be installed on transhipment nodes by shippers in a dynamic shipper carrier network under stochastic demand. A two stage linear program with recourse formulation is developed where in the first stage, the shipper decides the optimal capacity to be installed on transhipment nodes. In the second stage, the shipper chooses a routing strategy based on the realized demand. The performance of the following solution methods: Stochastic L Shaped Method, Regularized Decomposition and L Shaped Method with preliminary cuts were compared for various network sizes and numerous demand scenarios. A novel capacity shifting heuristic was introduced to generate a feasible implementable solution which significantly improves the performance of Regularized Decomposition and provides the best performance in the cases tested. Various ways of generating analytical bounds on the objective function value was discussed. The new capacity shifting heuristic was found to be efficient in generating tight upper bounds. Even though the formulation considered in this paper is for a single commodity, the model can be easily extended to account for multiple commodities.     

A Workflow Scheduling Method for Cloud Computing Platform

Wireless Personal Communications - Scheduling in computing environments such as homogeneous and heterogonous is very challenging and faces various difficulties computationally. This computing needs...