A Multistatic Uniform Diffraction Tomographic Algorithm for Real-Time Moisture Detection

To obtain the moisture distribution inside a polymer foam after drying in a conveyor belt system in real time, a Multistatic Uniform Diffraction Tomography (MUDT) imaging algorithm is proposed. It is estimated that MUDT provides a better spatial resolution than the original uniform diffraction tomography (UDT). Additionally, it allows to resolve the distribution of the different scatterers, which is shown by simulation result

The complementarities between Infomation and Communication Technologies Use, New Organizational Practices and Employee's Contextual Performance: Evidence from Europe in 2005 and 2010

International audienceThis article investigates the relationship between Information Technologies (IT), new organizational practices and workers' contextual performance in the European context. Our empirical results are based on data about more than 11000 employees from 16 European countries in 2005 and more than 16000 in 2010. First, we find asymmetric effects of IT use. Internet use is, indeed, positively related to all aspects of contextual performance in 2010, while computer use has been positively associated with contextual performance in 2005 but not in 2010. Second, we find that most of the considered new organizational practices have a positive relationship with employees' contextual performance.Cet article analyse les relations entre les Technologies de l'Information (TI), les nouvelles pratiques organisationnelles et la performance contextuelle des employés dans le contexte européen. Nos résultats empiriques sont basés sur des bases de données concernant plus de 11 000 employés de 16 pays européens en 2005 et plus de 16 000 en 2010. Premièrement, nos résultats soulignent des effets asymétriques de l'usage des TI. L'usage d'Internet est, en effet, positivement lié à tous les aspects de la performance contextuelle en 2010, tandis que l'usage de l'informatique est associé positivement seulement à la performance contextuelle interpersonnelle en 2005. Deuxièmement, nous constatons que la plupart des nouvelles pratiques organisationnelles considérées ont une relation positive avec la performance contextuelle des employés

Study of two-phase flow in helical and spiral coils

The principal purposes of the present study were to: (1) observe and develop a fundamental understanding of the flow regimes and their transitions occurring in helical and spiral coils; and (2) obtain pressure drop measurements of such flows, and, if possible, develop a method for predicting pressure drop in these flow geometries. Elaborating upon the above, the general intent is to develop criteria (preferably generalized) for establishing the nature of the flow dynamics (e.g. flow patterns) and the magnitude of the pressure drop in such configurations over a range of flow rates and fluid properties. Additionally, the visualization and identification of flow patterns were a fundamental objective of the study. From a practical standpoint, the conditions under which an annular flow pattern exists is of particular practical importance. In the possible practical applications which would implement these geometries, the working fluids are likely to be refrigerant fluids. In the present study the working fluids were an air-water mixture, and refrigerant 113 (R-113). In order to obtain records of flow patterns and their transitions, video photography was employed extensively. Pressure drop measurements were made using pressure differential transducers connected across pressure taps in lines immediately preceding and following the various test sections

Supporting visualization analysis in industrial process tomography by using augmented reality—A case study of an industrial microwave drying system

Industrial process tomography (IPT) based process control is an advisable approach in industrial heating processes for improving system efficiency and quality. When using it, appropriate dataflow pipelines and visualizations are key for domain users to implement precise data acquisition and analysis. In this article, we propose a complete data processing and visualizing workflow regarding a specific case—microwave tomography (MWT) controlled industrial microwave drying system. Furthermore, we present the up-to-date augmented reality (AR) technique to support the corresponding data visualization and on-site analysis. As a pioneering study of using AR to benefit IPT systems, the proposed AR module provides straightforward and comprehensible visualizations pertaining to the process data to the related users. Inside the dataflow of the case, a time reversal imaging algorithm, a post-imaging segmentation, and a volumetric visualization module are included. For the time reversal algorithm, we exhaustively introduce each step for MWT image reconstruction and then present the simulated results. For the post-imaging segmentation, an automatic tomographic segmentation algorithm is utilized to reveal the significant information contained in the reconstructed images. For volumetric visualization, the 3D generated information is displayed. Finally, the proposed AR system is integrated with the on-going process data, including reconstructed, segmented, and volumetric images, which are used for facilitating interactive on-site data analysis for domain users. The central part of the AR system is implemented by a mobile app that is currently supported on iOS/Android platforms

Playing with Data: An Augmented Reality Approach to Interact with Visualizations of Industrial Process Tomography

Industrial process tomography (IPT) is a specialized imaging technique widely used in industrial scenarios for process supervision and control. Today, augmented/mixed reality (AR/MR) is increasingly being adopted in many industrial occasions, even though there is still an obvious gap when it comes to IPT. To bridge this gap, we propose the first systematic AR approach using optical see-through (OST) head mounted displays (HMDs) with comparative evaluation for domain users towards IPT visualization analysis. The proof-of-concept was demonstrated by a within-subject user study (n=20) with counterbalancing design. Both qualitative and quantitative measurements were investigated. The results showed that our AR approach outperformed conventional settings for IPT data visualization analysis in bringing higher understandability, reduced task completion time, lower error rates for domain tasks, increased usability with enhanced user experience, and a better recommendation level. We summarize the findings and suggest future research directions for benefiting IPT users with AR/MR

A Combined Microwave Imaging Algorithm for Localization and Moisture Level Estimation in Multilayered Media

In this work, a multistatic uniform diffraction tomography (MUDT) method, that was proposed by the authors as a new qualitative imaging method just recently, is combined with the quantitative Bayesian inversion framework. In this combined approach, MUDT is applied to find the location of the moisture and this localization is employed as a pre-knowledge for the Bayesian framework to estimate the moisture levels in a polymer foam. The proposed combined algorithm might become a major part of the development of a new kind of intelligent industrial microwave drying systems. The imaging algorithm is tested with simulated measurement data. The frequency band from 8 GHz to 12 GHz (X-band) is used for the MUDT algorithm whereas a single frequency of 8.2 GHz is assumed for the Bayesian framework. The first results demonstrate the ability of the developed combined algorithm for optimizing the computational load unlike seen in the quantitative inversion approaches

An electromagnetic time-reversal imaging algorithm for moisture detection in polymer foam in an industrial microwave drying system

Microwave tomography (MWT) based control is a novel idea in industrial heating systems for drying polymer foam. In this work, an X-band MWT module is designed and developed using a fixed antenna array configuration and integrated with the HEPHAISTOS industrial heating system. A decomposition of the time-reversal operator (DORT) algorithm with a proper Green’s function of multilayered media is utilized to localize the moisture location. The derived Green’s function can be applied to the media with low or high contrast layers. It is shown that the time-reversal imaging (TRI) with the proposed Green’s function can be applied to the multilayered media with a moderately rough surface. Moreover, a single frequency TRI is proposed to decrease the measurement time. Numerical results for different moisture scenarios are presented to demonstrate the efficacy of the proposed method. The developed method is then tested on the experimental data for different moisture scenarios from our developed MWT experimental prototype. Image reconstruction results show promising capabilities of the TRI algorithm in estimating the moisture location in the polymer foam