Empirical models for net-length probability distribution and applications

In this paper, we propose a novel, empirical, and parameterizable model for estimating the probability distribution of wire length for each net in a placed netlist. The model is simple and fast to compute. We did extensive experimentation with state-of-the-art commercial (Cadence) and academic (Parquet and Labyrinth) tools and validated our model. Our distribution model was around three times more accurate than assuming half-perimeter bounding box as the fixed net-length estimate. Since the model is parameterizable it can be easily tailored for different routing tools and benchmarks. This model would be very useful in defining a full fledged probabilistic design automation methodology in which various design metrics are optimized from a probabilistic point of view. We also discuss the application of our model in a novel probabilistic approach to the buffer insertion problem.     

Incremental maintenance of aggregate and outerjoin expressions

Views stored in a data warehouse need to be kept current. As recomputing the views is very expensive, incremental maintenance algorithms are required. Over recent years, several incremental maintenance algorithms have been proposed. None of the proposed algorithms handle the general case of relational expressions involving aggregate and outerjoin operators efficiently.     

An Authentication Based Approach for Prevention of Spectrum Sensing Data Falsification Attacks in Cognitive Radio Network

Wireless Personal Communications - This is the era of Intelligent Cognitive Radio Network (CRN) technology that provides the available spectrum with efficient utilization. Cognitive Radio (CR)...     

Introducing robustness in multi-objective optimization

In optimization studies including multi-objective optimization, the main focus is placed on finding the global optimum or global Pareto-optimal solutions, representing the best possible objective values. However, in practice, users may not always be interested in finding the so-called global best solutions, particularly when these solutions are quite sensitive to the variable perturbations which cannot be avoided in practice. In such cases, practitioners are interested in finding the robust solutions which are less sensitive to small perturbations in variables. Although robust optimization is dealt with in detail in single-objective evolutionary optimization studies, in this paper, we present two different robust multi-objective optimization procedures, where the emphasis is to find a robust frontier, instead of the global Pareto-optimal frontier in a problem. The first procedure is a straightforward extension of a technique used for single-objective optimization and the second procedure is a more practical approach enabling a user to set the extent of robustness desired in a problem. To demonstrate the differences between global and robust multi-objective optimization principles and the differences between the two robust optimization procedures suggested here, we develop a number of constrained and unconstrained test problems having two and three objectives and show simulation results using an evolutionary multi-objective optimization (EMO) algorithm. Finally, we also apply both robust optimization methodologies to an engineering design problem.     

Influence of dietary iron deficiency on acute metal intoxication

The frequent difficulties encountered in the diagnosis of pediatric sarcomas, caused by the lack of observable differentiation at the light microscopic level, has led to the routine use of immunohistochemistry in pediatric surgical pathology. To a large degree the advent of this staining technique has led to the correct assessment of many perplexing lesions that previously would have been given inconclusive diagnoses. However, with increased usage and testing, it has become apparent that there are few, if any, "magic bullets" in immunohistochemistry for pediatric pathologists. Thus, it behooves diagnosticians to be careful in the usage of this technique, to be aware of possible discrepancies in its results, and to remember the ancillary nature of its application. The following article will review selected markers commonly used in pediatric surgical pathology, from both previous reports and the author's perspective, and will briefly consider several new phenotypic markers which have potential utility with childhood sarcomas.     

Hydrogen from empty cotton boll agro-waste via thermochemical route and feasibility study of operating an IC engine in continuous mode

Hydrogen can be cited as prospective source of clean power. In this work hydrogen rich syn-gas generated from the agro-waste, empty cotton bolls was injected into an IC engine in continuous mode along with gasoline. At the air-fuel ratio of 23.40, specific fuel consumption of 0.35 kg kWh^?1, the engine could be operated with higher efficiency than with gasoline alone. A distinct reduction in emission characteristics could also be seen. Empty cotton bolls derived after removal of cotton from the flower in field, was first studied for fuel properties. The reasonably high heating value (HHV) of 17.54 MJ kg^?1 suggested that it could be a precursor to hydrogen via two stepped thermo-chemical process. The first step involved slow pyrolysis of the biomass at 500 °C for 60 min at a heating rate of 10 °C min^?1 yielding 39.71% bio-char by weight. The C, H, N, S and O contents of the produced bio-char was 59.91, 2.91, 0.72, 0.47 and 35.99% respectively and its HHV was 26.7 MJ kg^?1. Steam gasification of this bio-char, at 700 °C and water flowrate of 7 mL min^?1 exhibited maximum hydrogen yield of 67.42% (v/v) in the syn-gas mixture. Subsequent enrichment of the gas using ethanolamine/ethylene diamine and KMnO₄ solutions resulted in more than 90% (v/v) hydrogen in the combustible gas mixture and the test engine could be effectively operated.     

Automatic synthesis of quaternary quantum circuits

Quaternary encoded binary circuits are more compact than their binary counterpart. Although quaternary reversible circuits are realizable, design of such circuits is still in its infancy. This work proposes a new, enhanced method of quaternary Galois field sum of products (QGFSOP) synthesis for quaternary quantum circuits. To reduce QGFSOP product terms, the algorithm makes use of 11 newly defined quaternary Galois field (QGF) expansions (for a total of 21 QGF expansions). This algorithm achieves QGFSOP minimization with the assistance of a pseudo-Kronecker Galois field decision diagram (QGFDD). This is a novel approach for QGFSOP synthesis. Finally, QGFSOP expressions are translated into quantum cost optimized quaternary quantum circuits using: (1) newly developed quaternary quantum gate realizations of controlled Feynman and Toffoli gate that are optimized in terms of quantum cost, (2) use of composite literals consisting of 1 digit and M–S gates. Performance evaluation against existing works in the literature determined that our proposed method achieves an average QGFSOP expression product term savings of 32.66 %. Also, the synthesized QGFSOP circuits were evaluated in terms of quantum cost.     

Crystallization of Stoichiometric SbSI Glass

Congruent crystallization of antimony sulphoiodide (SbSI) glass of stoichiometric composition, which is prepared successfully for the first time using rapid melt‐quenching, has been investigated using differential scanning calorimetry (DSC). The results for glass powder show a glass transition at 127°C and two separate exothermal peaks with maxima around 140°C and 190°C. The ratio of the intensities of the exothermal peak at ~190°C to the peak at ~140°C increases as the particle size and heating rate are increased, but their total enthalpy remains constant at 62 ± 2 J/g for all DSC runs. Surface heating of the glass induced by a 520 nm CW laser shows two contracted regions: needle‐like crystalline formations at low temperature and bulk crystallization at high temperature. The observed phenomena and DSC results suggest two different kinds of crystallization of the SbSI phase: one‐dimensional crystallization at low temperature which starts from the sample surface and three‐dimensional bulk crystallization that continues the transformation to crystalline state at higher temperatures. The origin of the two different crystallizations can be traced to the strong anisotropy of the SbSI crystal structure due to the weak van der Waals interaction between covalent‐ionic chains (Sb₂S₂I₂)_n.     

Effects of plasticizer/cross-linker on the mechanical and thermal properties of starch/PVA blends

Biodegradable blends of potato starch and polyvinyl alcohol were prepared by solution casting method. Citric acid was employed to introduce the plasticizing effect into the starch materials. Glutaraldehyde as cross-linker was used to enhance the properties of the blend films. Cross-linking is a common method to improve the strength and stability of starch products. The effects of citric acid and glutaraldehyde on the mechanical properties, thermal properties and swelling degree were investigated. The prepared films were measured for their antibacterial activities and biodegradability. The blend samples were characterized by the thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and FTIR analysis techniques. From the mechanical properties study, it was analyzed that the blend films showed improvement in their tensile strength after cross-linking with glutaraldehyde. The SEM micrographs indicated that the blend films were smooth without any cracks, pores and were well cross-linked. The TGA curves showed that there was an increase in the thermal stability of the blend films after cross-linking as compared to uncross-linked blend films. The prepared films showed good antibacterial properties against Gam-positive and Gram-negative bacteria. The biodegradability of the blends was determined by placing the samples in compost soil for different time intervals and were found to be biodegradable in nature.