Polynomial approximated phase-only multiple sector beam patterns of linear antenna arrays with pre-fixed amplitude distribution using real-valued genetic algorithms

In this paper, the authors present second degree polynomial approximated phase-only synthesis of two different types of symmetric sector or flat-top beams of equally spaced linear antenna arrays of isotropic radiators with single pre-fixed cosine on a pedestal amplitude distributions using real-coded or real-valued genetic algorithm. This gives a regular shape to the phase distributions of the radiators. Regular shape phase distributions result in simpler feed network design compared to irregular shape phase distributions. A good agreement between desired and synthesized pattern using genetic algorithm (GA) is reported.     

Efficient Pattern Generation for Small-Delay Defects Using Selection of Critical Faults

Testing for small-delay defects (SDDs) has become necessary as technology further scales. Existing tools and methodologies for generating SDD patterns suffer from: limited long-paths sensitization capability, overwhelming pattern volume, time-consuming pattern generation process, and vague evaluations of pattern quality. Such situation places patterns in a dilemma where the generation and application effort are huge yet the results cannot reflect the physical phenomena clearly enough for correct binning and diagnosis. In this paper, we focus on establishing a pattern generation flow that produces patterns of high application value. Firstly, critical faults are identified in order to generate high-quality original pattern repository with n-detect ATPG.A novelpattern evaluation and selection method that further minimizes pattern count while maintaining the SDD detection ability is then presented. Top-off ATPG is then performed to ensure meeting the target fault coverage. Along with the flow, multiple evaluation metrics are also proposed to measure the pattern’s efficiency on SDD coverage, unique SDD detection, detectable SDD size, long path distribution, etc. Experimental results demonstrate that the proposed critical fault-based method improves long path sensitization efficiency by 2.5× without impairing its average delay and saves approximately 80 % CPU runtime compared with total fault-based method. Comparing with timing-aware ATPG, the generated pattern set detects equivalent or even more SDDs with significantly reduced pattern count.     

Heat transfer correlation for high-porosity open-cell foam

Heat transfer correlation has been developed, assuming a simple cubic model of open-cell foam. The cross-linked porous structure is equivalent to a bundle of independent, slender tubes with protrusions. It may be presumed that the projected struts either cause an increase in heat transfer coefficient or they act as extended surfaces or fins. The effect of these protruded filaments has been judiciously integrated within the empirical correlation for cross-convective flow over the bank of smooth tubes. An augmentation in foam heat transfer coefficient has occurred due to cross-connections in struts. An excellent agreement has been observed between the predicted correlations and the existing ones which have been established through experimental data.     

Pricing decisions for three-echelon supply chain with advertising and quality effort-dependent fuzzy demand

Simultaneous influence of market power structure, advertising and quality efforts on the optimal pricing decisions and performance of a multi-echelon supply chain under uncertainty have received scant attention in the literature. We focus on this gap by examining a serial decentralised three-echelon supply chain consisting of a supplier, a manufacturer and a retailer. The uncertainty associated with customer demand, marginal production costs and effort costs is expressed as linguistic or fuzzy variables. We analyse centralised supply chain to obtain all benchmark parameters. We investigate four decentralised supply chain cases through fuzzy game theoretic approach. We compare among three Stackelberg games with various supply chain leaderships and a vertical Nash. Our key findings are as follows. First, the manufacturer puts least quality effort while retailer puts least advertising effort when they act as Stackelberg leader in a three-echelon supply chain. Second, supplier's per unit price is governed by the channel leadership in three-echelon supply chain while retail prices are less affected by the leadership. We investigate the impact of fuzzy degree of quality and advertising sensitivity on optimal profit distribution among agents. We present numerical analysis to illustrate the importance of the derived theoretical results and discuss additional managerial insights.     

Approximability of Sparse Integer Programs

The main focus of this paper is a pair of new approximation algorithms for certain integer programs. First, for covering integer programs {min cx:Ax≥b,0≤x≤d} where A has at most k nonzeroes per row, we give a k-approximation algorithm. (We assume A,b,c,d are nonnegative.) For any k≥2 and ε>0, if P≠NP this ratio cannot be improved to k−1−ε, and under the unique games conjecture this ratio cannot be improved to k−ε. One key idea is to replace individual constraints by others that have better rounding properties but the same nonnegative integral solutions; another critical ingredient is knapsack-cover inequalities. Second, for packing integer programs {max cx:Ax≤b,0≤x≤d} where A has at most k nonzeroes per column, we give a (2k ²+2)-approximation algorithm. Our approach builds on the iterated LP relaxation framework. In addition, we obtain improved approximations for the second problem when k=2, and for both problems when every A _ij is small compared to b _i . Finally, we demonstrate a 17/16-inapproximability for covering integer programs with at most two nonzeroes per column.     

RGO/MgO hybrid nanocomposites with high specific capacitance

A scalable, cost effective synthesis of reduced graphene oxide (RGO)-magnesium oxide (MgO) hybrid nanocomposite (RGOMOHNC) is reported in the present work. The process involves an in-situ sonication method in aqueous medium at room temperature e.g., 30 °C. The as synthesized graphene oxide (GO) and RGOMOHNC powders are characterized by the XRD, FESEM, TEM, FTIR, RS and XPS techniques. The results indicate that in-situ growth of 20–30 nm MgO nanoparticles effectively increases the graphitic nature of the layered RGO microstructure. The experimentally measured cyclic voltammetry (CV) plots show that the specific capacitance of the RGOMOHNC powders is three orders of magnitude higher than that of the GO powders. A mechanism of RGOMOHNC formation has been proposed.     

Space compaction of test responses using orthogonal transmission functions [logic testing]

Space compaction of test responses provides parallel access to functional outputs and reduces testing time and test data volume. We present a new space compaction approach that only uses information about the fault-free responses for a precomputed test set T. It is, therefore, especially suitable for embedded cores. It does not make any assumption about an underlying fault model, and it does not make use of any structural information about the core. Advantages of this approach include complete error propagation for all errors and optimum (provably maximum) compaction ratio. Classical linear space compactors often require structural information and can only guarantee error propagation for a specific fault model. In contrast, the proposed compactor design is based on the use of orthogonal transmission functions, which allow all errors produced by T to be propagated through the space compactor. We illustrate the proposed method by presenting case studies on compactor synthesis for several large ISCAS benchmark circuits. We show that maximum compaction with low area overhead can be achieved for circuits for which compact test sets are available.     

Comments on “Analysis of wide inclined slot coupled narrowwall coupler between dissimilar rectangular waveguides”[and reply]

Comments by D. Satyanarayana and Ajay Chakrabarty claim that the original paper [see IEEE Trans. Antennas Propagat., vol. AP-37, no. 9, p. 1116-23, 1989] has not considered the contribution of TE_no mode in the scattered fields in the waveguide region and imply that the Green's function employed is incomplete. However there is a discussion on the singular contribution with a mathematical expression containing the appropriate Dirac delta function. It is also obvious that the specific terms of the cavity Green' s functions that treat the waveguide wall thickness do not have such a singular contribution present. Therefore, Green's functions employed in the paper are complete and rigorous. D. Satyanarayana and Ajay Chakrabarty reply to these further comments by the original author     

Antimicrobial potentiality of a new beta-lactum antibiotic fosfomycin

Antimicrobial action of penicillin and some of its derivatives including fosfomycin was studied with respect to 225 strains of Gram-positive and Gram negative bacteria. Fosfomycin was found to possess somewhat less activity against Staphylococcus aureus compared with other penicillins; however, it showed powerful activity towards Escherichia coli, Klebsiella spp. and Proteus mirabilis.