53 research outputs found

    Two-Dimensional Digitized Picture Arrays and Parikh Matrices

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    Parikh matrix mapping or Parikh matrix of a word has been introduced in the literature to count the scattered subwords in the word. Several properties of a Parikh matrix have been extensively investigated. A picture array is a two-dimensional connected digitized rectangular array consisting of a finite number of pixels with each pixel in a cell having a label from a finite alphabet. Here we extend the notion of Parikh matrix of a word to a picture array and associate with it two kinds of Parikh matrices, called row Parikh matrix and column Parikh matrix. Two picture arrays A and B are defined to be M-equivalent if their row Parikh matrices are the same and their column Parikh matrices are the same. This enables to extend the notion of M-ambiguity to a picture array. In the binary and ternary cases, conditions that ensure M-ambiguity are then obtained

    Electrodeposition of Sn, Se, SnSe and the material properties of SnSe films

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    Tin sulphide (SnS) films have been electrodeposited and the materials properties are reported, The potential-pH diagram of Sn and S in aqueous medium are superimposed to obtain the common immunity domains which predicts a pH value 1.5 and deposition potential of ·1.0 VseE for the stoichiometric deposition. Films are cathodically deposited on 5002 coated conducting glass substrates at bath temperatures 303-353 K. XRD studies show the polycrystalline nature with orthorhombic structure. The optical band gap of the snS film is 1.1 eV from the absorption studies. ESCA spectrum confirms the presence of Sn and S on the grey black sample. Uniform, smooth and pin hole free surface morphology is observed by SEM

    MFO tunned SVR models for analyzing dimensional characteristics of cracks developed on steam generator tubes

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    Accurate prediction of material defects from the given images will avoid the major cause in industrial applications. In this work, a Support Vector Regression (SVR) model has been developed from the given Gray Level Co-occurrence Matrix (GLCM) features extracted from Magnetic Flux Leakage (MFL) images wherein the length, depth, and width of the images are considered response values from the given features data set, and a percentage of data has been considered for testing the SVR model. Four parameters like Kernel function, solver type, and validation scheme, and its value and % of testing data that affect the SVR model's performance are considered to select the best SVR model. Six different kernel functions, and three different kinds of solvers are considered as two validation schemes, and 10% to 30% of the testing data set of different levels of the above parameters. The prediction accuracy of the SVR model is considered by simultaneously minimizing prediction measures of both Root Mean Square Error (RMSE), and Mean Absolute Error (MAE) and maximizing R-2 values. The Moth Flame Optimization (MFO) algorithm has been implemented to select the best SVR model and its four parameters based on the above conflict three prediction measures by converting multi-objectives into a single object using the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) method. The performance of the MFO algorithm is compared statistically with the Dragon Fly Optimization Algorithm (DFO) and Particle Swarm Optimization Algorithm (PSO).Web of Science1223art. no. 1237

    Global burden of chronic respiratory diseases and risk factors, 1990–2019: an update from the Global Burden of Disease Study 2019

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    Background: Updated data on chronic respiratory diseases (CRDs) are vital in their prevention, control, and treatment in the path to achieving the third UN Sustainable Development Goals (SDGs), a one-third reduction in premature mortality from non-communicable diseases by 2030. We provided global, regional, and national estimates of the burden of CRDs and their attributable risks from 1990 to 2019. Methods: Using data from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019, we estimated mortality, years lived with disability, years of life lost, disability-adjusted life years (DALYs), prevalence, and incidence of CRDs, i.e. chronic obstructive pulmonary disease (COPD), asthma, pneumoconiosis, interstitial lung disease and pulmonary sarcoidosis, and other CRDs, from 1990 to 2019 by sex, age, region, and Socio-demographic Index (SDI) in 204 countries and territories. Deaths and DALYs from CRDs attributable to each risk factor were estimated according to relative risks, risk exposure, and the theoretical minimum risk exposure level input. Findings: In 2019, CRDs were the third leading cause of death responsible for 4.0 million deaths (95% uncertainty interval 3.6–4.3) with a prevalence of 454.6 million cases (417.4–499.1) globally. While the total deaths and prevalence of CRDs have increased by 28.5% and 39.8%, the age-standardised rates have dropped by 41.7% and 16.9% from 1990 to 2019, respectively. COPD, with 212.3 million (200.4–225.1) prevalent cases, was the primary cause of deaths from CRDs, accounting for 3.3 million (2.9–3.6) deaths. With 262.4 million (224.1–309.5) prevalent cases, asthma had the highest prevalence among CRDs. The age-standardised rates of all burden measures of COPD, asthma, and pneumoconiosis have reduced globally from 1990 to 2019. Nevertheless, the age-standardised rates of incidence and prevalence of interstitial lung disease and pulmonary sarcoidosis have increased throughout this period. Low- and low-middle SDI countries had the highest age-standardised death and DALYs rates while the high SDI quintile had the highest prevalence rate of CRDs. The highest deaths and DALYs from CRDs were attributed to smoking globally, followed by air pollution and occupational risks. Non-optimal temperature and high body-mass index were additional risk factors for COPD and asthma, respectively. Interpretation: Albeit the age-standardised prevalence, death, and DALYs rates of CRDs have decreased, they still cause a substantial burden and deaths worldwide. The high death and DALYs rates in low and low-middle SDI countries highlights the urgent need for improved preventive, diagnostic, and therapeutic measures. Global strategies for tobacco control, enhancing air quality, reducing occupational hazards, and fostering clean cooking fuels are crucial steps in reducing the burden of CRDs, especially in low- and lower-middle income countries

    Effects of fluoxetine on functional outcomes after acute stroke (FOCUS): a pragmatic, double-blind, randomised, controlled trial

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    Background Results of small trials indicate that fluoxetine might improve functional outcomes after stroke. The FOCUS trial aimed to provide a precise estimate of these effects. Methods FOCUS was a pragmatic, multicentre, parallel group, double-blind, randomised, placebo-controlled trial done at 103 hospitals in the UK. Patients were eligible if they were aged 18 years or older, had a clinical stroke diagnosis, were enrolled and randomly assigned between 2 days and 15 days after onset, and had focal neurological deficits. Patients were randomly allocated fluoxetine 20 mg or matching placebo orally once daily for 6 months via a web-based system by use of a minimisation algorithm. The primary outcome was functional status, measured with the modified Rankin Scale (mRS), at 6 months. Patients, carers, health-care staff, and the trial team were masked to treatment allocation. Functional status was assessed at 6 months and 12 months after randomisation. Patients were analysed according to their treatment allocation. This trial is registered with the ISRCTN registry, number ISRCTN83290762. Findings Between Sept 10, 2012, and March 31, 2017, 3127 patients were recruited. 1564 patients were allocated fluoxetine and 1563 allocated placebo. mRS data at 6 months were available for 1553 (99·3%) patients in each treatment group. The distribution across mRS categories at 6 months was similar in the fluoxetine and placebo groups (common odds ratio adjusted for minimisation variables 0·951 [95% CI 0·839–1·079]; p=0·439). Patients allocated fluoxetine were less likely than those allocated placebo to develop new depression by 6 months (210 [13·43%] patients vs 269 [17·21%]; difference 3·78% [95% CI 1·26–6·30]; p=0·0033), but they had more bone fractures (45 [2·88%] vs 23 [1·47%]; difference 1·41% [95% CI 0·38–2·43]; p=0·0070). There were no significant differences in any other event at 6 or 12 months. Interpretation Fluoxetine 20 mg given daily for 6 months after acute stroke does not seem to improve functional outcomes. Although the treatment reduced the occurrence of depression, it increased the frequency of bone fractures. These results do not support the routine use of fluoxetine either for the prevention of post-stroke depression or to promote recovery of function. Funding UK Stroke Association and NIHR Health Technology Assessment Programme

    Investigating the barriers to increase Levels of Automation. : A case study in pre-assembly of tap changer assembly line.

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    The overarching goal of this thesis is to investigate and explore the barriers that a company would face while increasing the Levels of Automation (LoA), in the preassembly production unit. To achieve the primary goal of investigating the barriers this study takes a threefold approach. Firstly, the current LoA was measured for the preassembly workstations. This measurement was conducted by incorporating an existing methodology adapted from the literature review known as DYNAMO++ methodology. This method is incorporated such that, the current LoA of the preassembly workstations could be measured and analysed. The current LoA of the preassembly workstations are analysed to investigate the potential workstations where LoA could be increased, in line with the company’s triggers for implementing automation. For this, experiences of the personnel’s belonging to the operational level of preassembly workstations were incorporated, to find the scope of improvements for increasing the LoA. Additionally, the company’s triggers for implementing automation was investigated from the managerial level. The research questions were answered by adapting an explorative, single case study method. Additionally, four types of data collection techniques were used, such as – interviews, focus groups, observations, and document analysis. Subsequently, source triangulation was adapted to analyse the data collected; to develop a comprehensive understanding of the barriers identified., Finally, the barriers faced by the company to increase LoA are identified by considering the implications that the improvement opportunities would impose upon the production systems environment. The identified barriers were then categorised further based on factors that exist internal as well as external to the production systems environment. The barriers identified in this study highlights various factors that the management must consider beforehand while initiating automation decisions in future automation projects in the preassembly area. Regardless of the barriers faced by the company, there are more opportunities to improve manufacturing processes through automation technologies. This thesis contributes to the knowledge of the factors that restrain the implementation of automation technologies and how companies could deal with it

    Electrodeposition of Sn, Se, SnSe and the material properties of SnSe films

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    A detailed account of the electrochemistry involved in the deposition of Sn, Se and SnSe ®lms is presented. The redox reactions and the polarization curves of Sn and Se were studied to ®x the pH and potential values V (NHE) to get uniform deposition. Films were cathodically deposited at 558C. XRD studies show an orthorhombic structure. Films showed an indirect band-gap of 1.05 eV. Surface morphological studies were carried out using SEM, and the stoichiometry was estimated from XPS analysis. Effect of annealing in air at 2008C has been reported

    Electrodeposition and optical properties of ZnxCd1-xS thin films

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    Electrodeposition technique has been used to deposit CdS-ZnCdS-ZnS solid solution films. Influence of Zn content in the solution on the band gap change is studied. Bandgap tailoring has been observed from 2.41 to 3.5 eV for the entire solid solutio

    Electrodeposition of Sn, Se, SnSe and the material properties of SnSe rlms

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    A detailed account of the electrochemistry involved in the deposition of Sn, Se and SnSe rlms is presented. The redox reactions and the polarization curves of Sn and Se were studied to rx the pH and potential values V (NHE) to get uniform deposition. Films were cathodically deposited at 558C. XRD studies show an orthorhombic structure. Films showed an indirect band-gap of 1.05 eV. Surface morphological studies were carried out using SEM, and the stoichiometry was estimated from XPS analysis. Effect of annealing in air at 2008C has been reported
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