A Non-Enumerative Technique for Measuring Path Correlation in Digital Circuits

The correlation between the physical paths of a digital circuit has important implications in various design automation problems, such as timing analysis, test generation and diagnosis. When considering the complexity and tight timing constraints of modern circuits, this correlation affects both the design process and the testing approaches followed in manufacturing. In this work we quantify the diversity of a set of paths (or path segments), let these be critical I/O paths, error propagation paths for various fault models, or paths traced for diagnostic purposes. Circuit paths are encoded using Zero-Suppressed Binary Decision Diagrams (ZBDDs); the proposed method consists of a sequence of standard ZBDD operations to provide a measure of the overlap of the paths under consideration. The main contribution of the presented method is that, path or path segment enumeration is entirely avoided and, hence, a large number of paths can be considered in practical time. Experimentation using standard benchmark circuits demonstrates the effectiveness of the approach in showing the difference in path correlation between various critical I/O path sets as well as propagation paths during test application.     

Review of multinomial and multiattribute quality control charts

Attribute control charts are very useful nowadays for monitoring processes where the quality characteristics cannot be measured in a continuous scale, which may be manufacturing processes from industrial settings, health‐care processes or processes from service industries and environments of non‐manufacturing quality‐improvement efforts. Many of the above cases, however, involve the monitoring of multiple attributes simultaneously, thus leading to the case of multinomial and multiattribute quality control methods, which are better than the simultaneous use of multiple uni‐attribute methods. In this study, an attempt to review the research previously conducted on multiattribute quality control is made in order to help the interested researchers and practitioners get informed about the references on the relevant research in this field, regarding the design, performance and applications of multiattribute control charts. Copyright © 2009 John Wiley & Sons, Ltd.     

Thermal decomposition behavior,characterization and evaluation of pyrolysis products of agricultural wastes

Thermal decomposition behavior during pyrolysis, the composition and the physicochemical characteristics of the pyrolysis products were studied for four agricultural wastes from Southern Greece. These wastes are produced in abundance in the Mediterranean Region but still remain relatively unexploited, while there is also lack or little relevant scientific information. Pyrolysis process for the examined samples was studied using a TGA analyzer and a properly tested and calibrated TG/MS setup, at a heating rate of 10 °C/min up to 850 °C. Determination of important quantitative parameters of pyrolysis as a function of temperature, on an instantaneous or integral basis, and correlation of the evolved gas results with the degradation of pseudocomponents of raw biomass was made possible. The average higher heating value of the pyrolysis light gases was found to be in a satisfactory for energy purposes range of 11.2–14.4 MJ/Nm³. Furthermore, biochars produced at 450, 550 and 650 °C in a fixed bed reactor were found to exhibit calorific value ranging from 20.1 to 28.7 MJ/kg and structural stability. They were also found to have a high nutrients content and below limits or negligible heavy metals content for soils applications, regardless of production temperature.     

Rain attenuation problems affecting the performance of microwave communication systems

Rain attenuation is considered to be a dominant factor affecting the reliability of both terrestrial and earth-to-satellite paths operating at frequencies above 10 GHz. The subject of the present paper is the development of some efficient models for the prediction of the operational characteristics (such as the path enlargement factor, accumulation thermal noise, site diversity improvement) of microwave systems operating at these frequencies. The numerical results taken from the present models have been compared with available experimental data from operated links in USA, Europe, Japan and the agreement has been found to be quite encouraging.     

Charge-coupled device spectrograph for direct solar irradiance and sky radiance measurements

The characterization of a charged-coupled device (CCD) spectrograph developed at the Laboratory of Atmospheric Physics, Thessaloniki is presented. The absolute sensitivity of the instrument for direct irradiance and sky radiance measurements was determined, respectively, with an uncertainty of 4.4% and 6.6% in the UV-B, and 3% and 6% in the UV-A, visible and near-infrared (NIR) wavelength ranges. The overall uncertainty associated with the direct irradiance and the sky radiance measurements is, respectively, of the order of 5% and 7% in the UV-B, increasing to 10% for low signals [e.g., at solar zenith angles (SZAs) larger than 70 degrees ], and 4% and 6% in the UV-A, visible, and NIR. Direct solar spectral irradiance measurements from an independently calibrated spectroradiometer (Bentham DTM 300) were compared with the corresponding CCD measurements. Their agreement in the wavelength range of 310-500nm is within 0.5% +/- 1.1% (for SZA between 20 degrees and 70 degrees ). Aerosol optical depth (AOD) derived by the two instruments using direct Sun spectra and by a collocated Cimel sunphotometer [Aerosol Robotic network (AERONET)] agree to within 0.02 +/- 0.02 in the range of 315-870 nm. Significant correlation coefficients with a maximum of 0.99 in the range of 340-360 nm and a minimum of 0.90 at 870 nm were found between synchronous AOD measurements with the Bentham and the Cimel instruments.     

Making assistive reading tools user friendly: a new platform for Greek dyslexic students empowered by automatic speech recognition

This work presents our effort to incorporate a state of the art speech recognition engine into a new platform for assistive reading for improving reading ability of Greek dyslexic students. This platform was developed in the framework of the Agent-DYSL, IST project, and facilitates dyslexic children in learning to read fluently. Unlike previously presented approaches, the aim of the system is not only to enable access to the reading materials within an inclusive learning system but to promote the development of reading skills by adjusting and adapting in the light of feedback to the system. The idea is to improve speech recognition performance so that gradually increase the reading capabilities of the user, gradually diminish the assistance provided, till he is able to read as a non-dyslexic reader. The evaluation results show that both learners’ reading pace and learners’ reading accuracy were increased.     

Controlled Fab installation onto polymeric micelle nanoparticles for tuned bioactivity

Abstract

Antibodies and antigen-binding fragments (Fabs) can be used to modify the surface of nanoparticles for enhanced target binding. In our previous work, site-specific conjugation of Fabs to polymeric micelles using conventional methods was limited to approximately 30% efficiency, possibly due to steric hindrance related to macromolecular reactants. Here, we report a new method that enables conjugation of Fabs onto a micelle surface in a controlled manner with up to quantitative conversion of nanoparticle reactive groups. Variation of (i) PEG spacer length in a heterofunctionalized cross-linker and (ii) Fab/polymer feed ratios resulted in production of nanoparticles with a range of Fab densities on the surface up to the theoretical maximum value. The biological impact of variable Fab density was evaluated in vitro with respect to cell uptake and cytotoxicity of a drug-loaded (SN38) targeted polymeric micelle bearing anti-EphA2 Fabs. Fab conjugation increased cell uptake and potency compared with non-targeted micelles, although a Fab density of 60% resulted in decreased uptake and potency of the targeted micelles. Altogether, our findings demonstrate that conjugation strategies can be optimized to allow control of Fab density on the surface of nanoparticles and also that Fab density may need to be optimized for a given cell-surface target to achieve the highest bioactivity.     

Rate-controlled constrained equilibrium: Formulation and application to nonpremixed laminar flames

Rate-controlled constrained equilibrium provides a sound framework for deriving and testing low-dimensional models of combustion chemistry, yet its application so far has been limited. The purpose of this paper is twofold: to propose a formulation of RCCE as a differential-algebraic problem and show how existing formulations such as the constraint potentials can be derived from it, and to demonstrate how combustion problems involving flow, such as nonpremixed laminar flames, can be solved with RCCE. A 9-constraint set is employed to reduce a 63-species detailed mechanism for CH₄-air combustion and is found to be sufficient for fairly accurate predictions of both ignition in a homogeneous reactor and the structure of nonpremixed laminar flames for a variety of strain rates, while the main features of the latter can also be reproduced with a 7-constraint subset.     

Formation of NOx precursors during the pyrolysis of coal and biomass. Part VIII. Effects of pressure on the formation of NH3 and HCN during the pyrolysis and gasification of Victorian brown coal in steam

Effects of pressure on the formation of HCN and NH₃ during the pyrolysis and gasification of Loy Yang brown coal in steam were investigated using a pressurised drop-tube/fixed-bed reactor. The NH₃ yield increased with increasing pressure during both pyrolysis and gasification. Increasing pressure selectively favours the formation of NH₃ at the expenses of other N-containing species. The changes in the yield of NH₃ with increasing pressure were mainly observed in the feeding periods both during pyrolysis and gasification and were closely related to the formation and subsequent cracking of soot both as a result of intensified thermal cracking of volatile precursors inside the particles and as a result of volatile-char interactions after the release of volatiles. While the corresponding HCN yield during pyrolysis showed little sensitivity to changes in pressure, the HCN yield during gasification in steam showed some increases with increasing pressure. Our data indicate that the direct hydrogenation of char-N by H radicals, favoured by the presence of steam, is the main route of NH₃ formation during pyrolysis and gasification. The direct conversion, either through hydrogenation or hydrolysis, of HCN into NH₃ on char surface during the pyrolysis and gasification of brown coal is not an important route of NH₃ formation.