Advanced Model of Eddy-Current NDE Inverse Problem with Sparse Grid Algorithm

In model-based inverse problem, some unknown parameters need to be estimated. These parameters are used not only to characterize the physical properties of cracks, but also to describe the position of the probes (such as lift off and angles) in the calibration. After considering the effect of the position of the probes in the inverse problem, the accuracy of the inverse result will be improved.With increasing the number of the parameters in the inverse problems, the burden of calculations will increase exponentially in the traditional full grid method. The sparse grid algorithm which introduced by Sergey A. Smolyak was used in our work. With this algorithm, we obtain a powerful interpolation method that requires significantly fewer support nodes than conventional interpolation on a full grid. In this work,we combined sparse grid toolbox TASMANIAN which is produced by Oak Ridge National Laboratory and professional eddy-current NDE software VIC-3D®to solve a specific inverse problem. An advanced model based on our previous one is used to estimate depth and width of the crack, lift off and two angles of the position of probes. Considering the calibration process, pseudorandom noise is considered in the model and statistics behavior is discussed

Advances in developing multiscale flaw models for eddy-current NDE

The need to accurately model multiscale phenomena is ubiquitous in eddy-current nondestructive evaluation. By using volume-integral equations, we are able to develop a very simple algorithm for accurately computing the response of a very small anomaly in the presence of a much larger one. We validate the algorithm and its associated code inVIC-3D{copyright, serif} through benchmark data on two test sets: (1) a notch at a bolt hole with an upper surface coil, and (2) a notch in a bolt hole with a plate surface coil

Recent Developments in Modeling Eddy-Current Probe-Flaw Interactions

A number of industries have been traditional users of eddy-current technology in nondestructive evaluation (NDE). The traditional mode of eddy-current inspection has been ‘monostatic,’ in which a single probe is used as both a ‘transmitter’ and ‘receiver’ Research in these industries now indicates the value of using ‘bistatic,’ or even ‘multistatic’ probe configurations, in which a single probe is used as a transmitter, and one or more probes are used as receivers. The probes may be either air core, or ferrite core, or perhaps a combination. Some examples of bistatic configurations are the split-core differential probe, and remote-field probes. The industry is turning to computer codes that are based on sophisticated computational electromagnetics algorithms in order to design these probes, and to interpret the signals that arise from the interaction of these probes with flaws

Model-based Probe State Estimation and Crack Inverse Methods Addressing Eddy Current Probe Variability

Recent work on model-based inverse methods with eddy current inspections of surface breaking discontinuities has shown some sizing error due to variability in probes with the same design specifications [1]. This is an important challenge for model-based inversion crack sizing techniques, to be robust to the varying characteristics of eddy current probes found in the field [1-2]. In this paper, a model-based calibration process is introduced that estimates the state of the probe. First, a carefully designed surrogate model was built using VIC-3D® simulations covering the critical range of probe rotation angles, tilt in two directions, and probe offset (liftoff) for both tangential and longitudinal flaw orientations. Some approximations and numerical compromises in the model were made to represent tilt in two directions and reduce simulation time; however, this surrogate model was found to represent the key trends in the eddy current response for each of the four probe properties in experimental verification studies well. Next, this model was incorporated into an iterative inversion scheme during the calibration process, to estimate the probe state while also addressing the gain/phase fit and centering the calibration notch indication. Results are presented showing several examples of the blind estimation of tilt and rotation angle for known experimental cases with good agreement within +/- 2.5 degrees. The RMS error was found to be significantly reduced by fitting the probe state and, in many instances, probe state estimation addresses the previously un-modelled characteristics (model error) with real probe inversion studies. Additional studies are presented comparing the size of the calibration notch and the quality of the calibration fit, where calibrating with too small or too large a notch can produce poorer inversion results. Once the probe state is estimated, the final step is to transform the base crack inversion surrogate model and apply it for crack characterization. Because of the dimensionality of this problem, simulations were made at a limited set of select flaw sizes with varying length, depth and width, and an interpolation scheme was used to address the effect of the probe state at intermediate solution points. Using this process, results are presented demonstrating improved crack inversion performance for extreme probe states

Gender differences in behavioral regulation in four societies: The United States, Taiwan, South Korea, and China

The current study investigates gender differences in behavioral regulation in four societies: the United States, Taiwan, South Korea, and China. Directly assessed individual behavioral regulation (Head–Toes–Knees–Shoulders, HTKS), teacher-rated classroom behavioral regulation (Child Behavior Rating Scale, CBRS) and a battery of school readiness assessments (mathematics, vocabulary, and early literacy) were used with 814 young children (ages 3–6 years). Results showed that girls in the United States had significantly higher individual behavioral regulation than boys, but there were no significant gender differences in any Asian societies. In contrast, teachers in Taiwan, South Korea, as well as the United States rated girls as significantly higher than boys on classroom behavioral regulation. In addition, for both genders, individual and classroom behavioral regulation were related to many aspects of school readiness in all societies for girls and boys. Universal and culturally specific findings and their implications are discussed

Global, regional, and national cancer incidence, mortality, years of life lost, years lived with disability, and disability-Adjusted life-years for 29 cancer groups, 1990 to 2017 : A systematic analysis for the global burden of disease study

Importance: Cancer and other noncommunicable diseases (NCDs) are now widely recognized as a threat to global development. The latest United Nations high-level meeting on NCDs reaffirmed this observation and also highlighted the slow progress in meeting the 2011 Political Declaration on the Prevention and Control of Noncommunicable Diseases and the third Sustainable Development Goal. Lack of situational analyses, priority setting, and budgeting have been identified as major obstacles in achieving these goals. All of these have in common that they require information on the local cancer epidemiology. The Global Burden of Disease (GBD) study is uniquely poised to provide these crucial data. Objective: To describe cancer burden for 29 cancer groups in 195 countries from 1990 through 2017 to provide data needed for cancer control planning. Evidence Review: We used the GBD study estimation methods to describe cancer incidence, mortality, years lived with disability, years of life lost, and disability-Adjusted life-years (DALYs). Results are presented at the national level as well as by Socio-demographic Index (SDI), a composite indicator of income, educational attainment, and total fertility rate. We also analyzed the influence of the epidemiological vs the demographic transition on cancer incidence. Findings: In 2017, there were 24.5 million incident cancer cases worldwide (16.8 million without nonmelanoma skin cancer [NMSC]) and 9.6 million cancer deaths. The majority of cancer DALYs came from years of life lost (97%), and only 3% came from years lived with disability. The odds of developing cancer were the lowest in the low SDI quintile (1 in 7) and the highest in the high SDI quintile (1 in 2) for both sexes. In 2017, the most common incident cancers in men were NMSC (4.3 million incident cases); tracheal, bronchus, and lung (TBL) cancer (1.5 million incident cases); and prostate cancer (1.3 million incident cases). The most common causes of cancer deaths and DALYs for men were TBL cancer (1.3 million deaths and 28.4 million DALYs), liver cancer (572000 deaths and 15.2 million DALYs), and stomach cancer (542000 deaths and 12.2 million DALYs). For women in 2017, the most common incident cancers were NMSC (3.3 million incident cases), breast cancer (1.9 million incident cases), and colorectal cancer (819000 incident cases). The leading causes of cancer deaths and DALYs for women were breast cancer (601000 deaths and 17.4 million DALYs), TBL cancer (596000 deaths and 12.6 million DALYs), and colorectal cancer (414000 deaths and 8.3 million DALYs). Conclusions and Relevance: The national epidemiological profiles of cancer burden in the GBD study show large heterogeneities, which are a reflection of different exposures to risk factors, economic settings, lifestyles, and access to care and screening. The GBD study can be used by policy makers and other stakeholders to develop and improve national and local cancer control in order to achieve the global targets and improve equity in cancer care. © 2019 American Medical Association. All rights reserved.Peer reviewe

Intraperitoneal drain placement and outcomes after elective colorectal surgery: international matched, prospective, cohort study

Despite current guidelines, intraperitoneal drain placement after elective colorectal surgery remains widespread. Drains were not associated with earlier detection of intraperitoneal collections, but were associated with prolonged hospital stay and increased risk of surgical-site infections.Background Many surgeons routinely place intraperitoneal drains after elective colorectal surgery. However, enhanced recovery after surgery guidelines recommend against their routine use owing to a lack of clear clinical benefit. This study aimed to describe international variation in intraperitoneal drain placement and the safety of this practice. Methods COMPASS (COMPlicAted intra-abdominal collectionS after colorectal Surgery) was a prospective, international, cohort study which enrolled consecutive adults undergoing elective colorectal surgery (February to March 2020). The primary outcome was the rate of intraperitoneal drain placement. Secondary outcomes included: rate and time to diagnosis of postoperative intraperitoneal collections; rate of surgical site infections (SSIs); time to discharge; and 30-day major postoperative complications (Clavien-Dindo grade at least III). After propensity score matching, multivariable logistic regression and Cox proportional hazards regression were used to estimate the independent association of the secondary outcomes with drain placement. Results Overall, 1805 patients from 22 countries were included (798 women, 44.2 per cent; median age 67.0 years). The drain insertion rate was 51.9 per cent (937 patients). After matching, drains were not associated with reduced rates (odds ratio (OR) 1.33, 95 per cent c.i. 0.79 to 2.23; P = 0.287) or earlier detection (hazard ratio (HR) 0.87, 0.33 to 2.31; P = 0.780) of collections. Although not associated with worse major postoperative complications (OR 1.09, 0.68 to 1.75; P = 0.709), drains were associated with delayed hospital discharge (HR 0.58, 0.52 to 0.66; P < 0.001) and an increased risk of SSIs (OR 2.47, 1.50 to 4.05; P < 0.001). Conclusion Intraperitoneal drain placement after elective colorectal surgery is not associated with earlier detection of postoperative collections, but prolongs hospital stay and increases SSI risk

Cure de volumineuses éventrations abdominales par technique de séparation antérieure des composants avec préservation des perforants assistée par cœlioscopie

INTRODUCTION. Les traitements des éventrations abdominales sont en constante évolution. L’essor des prothèses pariétales a constitué un avènement majeur dans la prise en charge de celle-ci. L’utilisation de prothèse synthétiques étaient initialement limité par le risque septique. La découverte des prothèses biologiques a permis d’étendre les indications de réparation pariétale prothétique. De nos jours la réparation prothétique s’impose comme le traitement de référence pour quasiment tous les types d’éventrations, de la plus petite a la plus large, du terrain le plus propice au patient atteint de comorbidité multiples et sévères, du terrain aseptique au terrain septique. Cependant la chirurgie prothétique ne saurait à elle seule prendre en charge 100% des éventrations. La population de patients étant atteinte d’éventrations se caractérise en majorité par certains facteurs de risque comme l’obésité ou le diabète rendant quelques fois insuffisante voire impossible la réparation pariétale prothétique seule. C’est dans ces situations que l’utilisation conjointe ou exclusive des techniques d’autoplastie, qu’elle soit antérieure ou postérieure, laparoscopique ou cœlioscopique tiennent tout leur intérêt. OBJECTIFS. Cet ouvrage récapitule les différentes prises en charge possible des éventrations, laparoscopique ou cœlioscopique, prothétiques, par raphie simple ou par autoplastie. Il décrit une technique d’autoplastie par séparation antérieure des composants assistée par cœlioscopie jamais décrite jusqu’ici dans la littérature et qui a été développée dans le service de chirurgie plastique du Professeur Jean Philippe GIOT à Grenoble. MATERIEL ET METHODES. Ce travail a d’abord consisté en une large revue de la littérature sur l’anatomie de la paroi abdominale, la physiopathologie de l’éventration et la prise en charge de celle-ci. Il reprend l’anatomie décrite dans les livres, les travaux anciens qui font le terreau des traitements actuels, les thèses de chirurgiens digestifs qui synthétisent avec brio le travail effectué jusqu’ici et les articles plus récents qui définissent les dernières avancées en matière de reconstruction pariétale et qui ont servis de base pour la conception de notre technique. Enfin il y présente des cas de patients pris en charge à l’aide de notre technique. RESULTATS. Cette thèse se divise en plusieurs partie, une première décrivant l’anatomie descriptive, physiologique puis pathologie des éventrations, une seconde décrivant les éventrations elles-mêmes, leur évolution, leurs complications, leurs facteurs de risques et leur incidence, une troisième décrivant la prise en charge de celles-ci allant de la raphie simple jusqu’au autoplasties en passant par le traitement prothétique et la prise en charge par cœlioscopie. Enfin une quatrième partie décrivant notre technique et les cas de patients pris en charge dans notre service à l’aide de celle-ci. CONCLUSION. L’avènement des prothèses synthétiques tend à s’imposer comme le traitement de référence des éventrations, néanmoins les autoplasties restent nécessaires dans certains cas extrêmes, notre technique vient s’ajouter aux nombreuses techniques décrites récemment et permet d’élargir l’éventail des possibilités de reconstruction pariétale disponible pour les chirurgiens

Unbalance in Alternating Current Rotating Machines

Abstract not availabl

Advanced Model of Eddy-Current NDE Inverse Problem with Sparse Grid Algorithm

In model-based inverse problem, some unknown parameters need to be estimated. These parameters are used not only to characterize the physical properties of cracks, but also to describe the position of the probes (such as lift off and angles) in the calibration. After considering the effect of the position of the probes in the inverse problem, the accuracy of the inverse result will be improved.With increasing the number of the parameters in the inverse problems, the burden of calculations will increase exponentially in the traditional full grid method. The sparse grid algorithm which introduced by Sergey A. Smolyak was used in our work. With this algorithm, we obtain a powerful interpolation method that requires significantly fewer support nodes than conventional interpolation on a full grid. In this work,we combined sparse grid toolbox TASMANIAN which is produced by Oak Ridge National Laboratory and professional eddy-current NDE software VIC-3D®to solve a specific inverse problem. An advanced model based on our previous one is used to estimate depth and width of the crack, lift off and two angles of the position of probes. Considering the calibration process, pseudorandom noise is considered in the model and statistics behavior is discussed.</p