50 research outputs found

    A Novel Multiple Classifier Generation and Combination Framework Based on Fuzzy Clustering and Individualized Ensemble Construction

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    Multiple classifier system (MCS) has become a successful alternative for improving classification performance. However, studies have shown inconsistent results for different MCSs, and it is often difficult to predict which MCS algorithm works the best on a particular problem. We believe that the two crucial steps of MCS - base classifier generation and multiple classifier combination, need to be designed coordinately to produce robust results. In this work, we show that for different testing instances, better classifiers may be trained from different subdomains of training instances including, for example, neighboring instances of the testing instance, or even instances far away from the testing instance. To utilize this intuition, we propose Individualized Classifier Ensemble (ICE). ICE groups training data into overlapping clusters, builds a classifier for each cluster, and then associates each training instance to the top-performing models while taking into account model types and frequency. In testing, ICE finds the k most similar training instances for a testing instance, then predicts class label of the testing instance by averaging the prediction from models associated with these training instances. Evaluation results on 49 benchmarks show that ICE has a stable improvement on a significant proportion of datasets over existing MCS methods. ICE provides a novel choice of utilizing internal patterns among instances to improve classification, and can be easily combined with various classification models and applied to many application domains

    Dynamic model with factors of polycystic ovarian syndrome in infertile women

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    Background: Previous studies present various methods for prediction disease based on statistics or neural networks.These models use statistics and results from past procedures to provide prediction through probability analysis. Objective: In this article, the authors present a dynamic model aiming at predicting the treatment result of infertile women with the factor of polycystic ovary syndrome. Materials and Methods: For this purpose, the authors have divided the study population into five groups: women prone to infertility, PCOS women, infertile women undergoing the treatment with Clomiphene Citrate and Gonadotropin, infertile women under IVF treatment, and improved infertile women. Therefore, the authors modeled the disease in infertile women mathematically and indicated that the free equilibrium point was asymptotically stable. Also the possibility of other equilibrium point of the system has been studied. Results: The authors showed that this equilibrium point was marginally stable. Using Stoke’s Theorem, the authors proved that the recurrence of the disease cycle with the factor of polycystic ovary syndrome was not intermittent in infertile women. They solved this model numerically using Rung-Kutta method and sketched the figures of the resulted solutions. Conclusion: It shows that with increasing age, the ovarian reserve is decreased and the treatment Clomiphene Citrate and Gonadotropin are not responsive, so IVF treatment is recommended in this group of patients considering the graphs of the model

    Insight into an Integrated Evaluation of Unmitigated Disposal Options for the Largest Waste Disposal Site in Tehran Using Rapid Impact and Sustainability Assessment Method

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    This study integrated the rapid impact assessment matrix (RIAM) analysis and the mathematical sustainability modeling to evaluate disposal options so as to find the most appropriate and practical unmitigated option for the main waste disposal site in Tehran, Iran. RIAM analysis was used to assess environmental impacts of five potential disposal options followed by determination of sustainability for each option. RIAM analysis results indicated that option 5 (i.e., composting) had the least negative cumulative impacts on the environmental score value of -481 among the studied options. Incineration of wastes, option 4, was found to be the least favorable option mainly due to the high relevant costs and emission of air pollutants. Option 3, sanitary landfilling, was found to have fewer negative impacts compared to the options 1 (open dumping), 2 (land burial), and 4. It was also found that none of the examined options were sustainable in unmitigated state; however, results indicated that option 5 was the most favorable one in terms of sustainability with an obtained sustainable value of -0.126, which was the lowest value of unsustainability found in the present study. Calculated values of environment for the evaluated options in unmitigated state were not sufficient enough to compensate for the corresponding values of human needs and interests. Finally, option 5 followed by option 3 were suggested as alternative disposal approaches for the current methods in unmitigated state to reduce negative environmental impacts of waste disposal

    The Construct of Willingness to Communicate and Its Relationship with EFL Learners’ Perceived Verbal and Nonverbal Teacher Immediacy

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    Given the fact that developing an intimate relationship between teacher and students creates a safe learning environment (Harran, 2006), and because teacher immediacy is proved to increase students’ motivation for learning (Velez & Cano, 2008), this study was an attempt to explore the relationship between Iranian EFL learners’ perceived teacher immediacy and their willingness to communicate (WTC). To this end, first, a new WTC questionnaire, specific to EFL settings, was developed, piloted, factor analyzed, and then administered on 90 intermediate EFL learners. In the second phase, the participants were required to complete Gorham’s (1988) Verbal Immediacy Measure (VIM) and McCroskey et al.’s (1996) Revised Nonverbal Immediacy Measure (RNIM). The findings revealed that there are 7 factors underlying EFL learners’ WTC, one of which is teacher immediacy. Further analyses showed that there is a positive relationship between both verbal and nonverbal teacher immediacy behaviors and EFL learners’ WTC in EFL classes. It can be concluded that teacher immediacy is one of the constituents of EFL learners’ WTC and that their WTC is likely to increase when teachers demonstrate immediacy behaviors while teaching. The present study has implications for language practitioners as well as teacher trainers

    Developing a Competency Model for EAP Teachers: Insights from Internationalization of Higher Education

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    The teachers' competencies in the process of internationalization of higher education (IHE) are of vital importance (Brandenburg & Federkeil, 2007; van der Werf, 2012). The extent of IHE in a university is in a close relationship with the teachers' competencies (Harari, 1981). However, the required competencies of teachers in IHE are not a well-studied topic. Similarly, the "dearth of literature on EAP professional development" (Blaj-Ward, 2014, p. 113) has complicated exploring the EAP teachers' competencies. The absence of a competency model addressing the needs of EAP teachers to effectively engage in the education fitting the IHE objectives and policies gave impetus to this study. In line with this objective, an instrument measuring EAP teachers' competencies was designed and validated. The following steps were taken to develop the instrument: the theme extraction and item generation phase, the piloting phase, and the validation phase. The extensive review of the literature and interviews with IHE experts and EAP teachers yielded 8 competencies. This initial framework led to the development of the preliminary version of a 22-item questionnaire. The piloting phase resulted in 23 items. 74 EAP teachers from both camps (language and content) participated in the final administration. Various factor analyses, internal consistency, and correlation of all of the items were performed. The data obtained confirmed a sufficiently reliable and valid scale, consisting of 6 components (with the same underlying themes of 8 competencies extracted earlier) and 23 items for measuring the EAP teachers' competencies

    Supplemental irrigation management of rainfed grapevines under drought conditions using the CropSyst model

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    Aim of study: To determine how much water should be used and when it should be applied in rain-fed grapevine using a cropping system simulation model (CropSyst), and also the economic analysis of supplemental irrigation for rainfed grapevine.Area of study: This study was conducted at the School of Agriculture, Shiraz University, Shiraz, Iran, in 2012, 2013 and 2014.Material and methods: The CropSyst model was calibrated to predict the rainfed yields of ‘Askari’ and ‘Yaghooti’ grapevines in different climates using four amounts of SI: 250 L (I1), 500 L (I2), 1000 L (I3) and 0 (I4), five SI times: single in March (T1), single in April (T2), single in March + single in April (T3), single in May (T4) and single in June (T5).Main results: Treatment T3 increased the average simulated yield of ‘Askari’ by 15% to 40% at regions with P/ETo>0.6, 17% to 61% at 0.2<P/ETO<0.6, and 26% to 61% at P/ETO<0.2, while in ‘Yaghooti’ it increased about 2% to 41% at regions with P/ETo>0.6, 4% to 36% at 0.2<P/ETO<0.6 and 2% to 26% at P/ETO<0.2. By increasing the water price by 30% and 50%, net benefits for the ‘Askari’ decreased by about 31% and 54%, while 6% and 18%, for ‘Yaghooti’ respectively.Research highlights: The CropSyst model can successfully predict soil water content and grapevine yields. Application of SI in May increased significantly the grapevine yield as compared to other SI times

    Tissue Reaction and Biocompatibility of Implanted Mineral Trioxide Aggregate with Silver Nanoparticles in a Rat Model

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    Introduction: Biocompatibility and antimicrobial activity of endodontic materials are of utmost importance. Considering the extensive applications of mineral trioxide aggregate (MTA) in dentistry and antimicrobial properties of silver nanoparticles, this study aimed to evaluate the subcutaneous inflammatory reaction of rat connective tissues to white MTA with and without nanosilver (NS) particles. Methods and Materials: Polyethylene tubes (1.1×8 mm) containing experimental materials (MTA and MTA+NS and empty control tubes) were implanted in subcutaneous tissues of seventy-five male rats. Animals were divided into five groups (n=15) according to the time of evaluation: group 1; after 7 days, group 2; after 15 days, group 3; after 30 days, group 4; after 60 days and group 5; after 90 days. The inflammatory reaction was graded and data was analyzed using the Kruskal-Wallis and Mann-Whitney U tests. Statistical significance was defined at 0.05. Results: Comparison of cumulative inflammatory reaction at all intervals revealed that the mean grade of inflammatory reaction to MTA, MTA+NS and control samples were 3, 2 and 2, respectively. According to the Mann-Whitney analysis there were no significant differences between MTA+NS and MTA (P=0.42). Conclusion: Incorporation of 1% nanosilver to MTA does not affect the inflammatory reaction of subcutaneous tissue in rat models.Keywords: Biocompatibility; Mineral Trioxide Aggregate; Nanosilver; Silver Nanoparticl

    Effects of N-acetylcysteine on aging cell and obesity complications in obese adults: a randomized, double-blind clinical trial

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    BackgroundWe decided to conduct this study with the aim of investigating the effects of N-Acetylcysteine (NAC) on obesity complications and senescence of visceral adipose tissue in obese adults.Methods and analysisThe present study was conducted as a randomized clinical trial (RCT) (Clinical trial registry number: IRCT20220727055563N1) on 40 obese adults candidates for bariatric surgery, who were randomly assigned to receive 600 mg of NAC (n = 20) or placebo as a control (n = 20) for 4 weeks. During bariatric surgery, visceral adipose tissue was used to examine gene expression and senescence cells using SA-β-gal.ResultsOur findings showed that intervention with NAC significantly reduces SA-β-gal activity (as a marker of senescence) and expression of p16 and interleukin 6 (IL-6) genes in the visceral adipose tissue compared to placebo in obese adults for 4 weeks. In addition, our findings showed the potential and beneficial effect of NAC administration on reducing the levels of inflammatory factors including IL-6 and high-sensitivity C-reactive protein (hs-CRP), as well as the level of fasting blood sugar (FBS), homeostatic model assessment of insulin resistance (HOMA-IR), and insulin compared to placebo after adjusting for confounders. No significant effect was indicated on anthropometric factors and lipid profile.ConclusionFindings showed that NAC, in addition to having a potential beneficial effect on reducing some of the complications caused by obesity, seems to have synolytic/senomorphic potential as well.Clinical trial registration[https://clinicaltrials.gov/], identifier [IRCT20220727055563N1]

    Gene selection for optimal prediction of cell position in tissues from single-cell transcriptomics data.

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    Single-cell RNA-sequencing (scRNAseq) technologies are rapidly evolving. Although very informative, in standard scRNAseq experiments, the spatial organization of the cells in the tissue of origin is lost. Conversely, spatial RNA-seq technologies designed to maintain cell localization have limited throughput and gene coverage. Mapping scRNAseq to genes with spatial information increases coverage while providing spatial location. However, methods to perform such mapping have not yet been benchmarked. To fill this gap, we organized the DREAM Single-Cell Transcriptomics challenge focused on the spatial reconstruction of cells from the Drosophila embryo from scRNAseq data, leveraging as silver standard, genes with in situ hybridization data from the Berkeley Drosophila Transcription Network Project reference atlas. The 34 participating teams used diverse algorithms for gene selection and location prediction, while being able to correctly localize clusters of cells. Selection of predictor genes was essential for this task. Predictor genes showed a relatively high expression entropy, high spatial clustering and included prominent developmental genes such as gap and pair-rule genes and tissue markers. Application of the top 10 methods to a zebra fish embryo dataset yielded similar performance and statistical properties of the selected genes than in the Drosophila data. This suggests that methods developed in this challenge are able to extract generalizable properties of genes that are useful to accurately reconstruct the spatial arrangement of cells in tissues
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