660 research outputs found

    Parametric Study of Continuous Concrete Beam Prestressed with External Tendon

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    This paper presents the results of a parametric study of the flexural behavior of continuous concrete members prestressed with external tendons. The behavior at ultimate limit states is evaluated. A nonlinear analysis model, based on the three dimensional finite element method, ANSYS computer program (10.0) was used. The nonlinear material and geometrical analysis were adopted. The results obtained show good agreement with experimental results. This research was carried out to study the effects of several factors on the overall behavior of externally prestressed beams in terms of the values of compressive concrete strength and effective prestressing stress. That behavior was slightly affected compared with experimental results. The undeviated external tendons mobilized lower nominal flexural resistance and inelastic deflection than deviated tendons did. The increase in the beam capacity in the beam subjected to loads at the third span is greater than in the beam with a single load at the mid – span. The result of increasing the effective depth is that the ultimate load capacity is essentially increased

    New Entropy Estimators with Smaller Root Mean Squared Error

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    New estimators of entropy of continuous random variable are suggested. The proposed estimators are investigated under simple random sampling (SRS), ranked set sampling (RSS), and double ranked set sampling (DRSS) methods. The estimators are compared with Vasicek (1976) and Al-Omari (2014) entropy estimators theoretically and by simulation in terms of the root mean squared error (RMSE) and bias values. The results indicate that the suggested estimators have less RMSE and bias values than their competing estimators introduced by Vasicek (1976) and Al-Omari (2014)

    Assuring the Quality of the Course Learning Outcomes Assessment Process

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    [EN] Learning Outcomes Assessment (LOA) provide educators with a practical instrument to review and enhance the alignment between the planned, delivered and experienced curriculum. Effective LOA processes help educators decide on the proper actions to take and the strategies to implement in order to ensure the continuous improvement of the student learning experience, and the attainment of the intended learning outcomes. Nonetheless, the adoption of LOA in higher education is still lagging and the assessment loop is rarely closed. This is mainly due to the indigent implementation of the assessment processes, and the vague definition of the responsibilities and quality assurance measures. This paper introduces a committee infrastructure to foster accountability and responsibility and assure the quality of the implemented assessment processes. The infrastructure has been established syccessfully over the last few years, and a noticeable improve in the execution of the assessment process has been detected.Ibrahim, W.; Amer, H. (2021). Assuring the Quality of the Course Learning Outcomes Assessment Process. En 7th International Conference on Higher Education Advances (HEAd'21). Editorial Universitat Politècnica de València. 763-771. https://doi.org/10.4995/HEAd21.2021.13051OCS76377

    Acceptance Sampling Plans Based on Truncated Life Tests for Sushila Distribution

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    An acceptance sampling plan problem based on truncated life tests when the lifetime following a Sushila distribution is considered in this paper. For various acceptance numbers, confidence levels and values of the ratio between fixed experiment time and particular mean lifetime, the minimum sample sizes required to ascertain a specified mean life were found. The operating characteristic function values of the suggested sampling plans and the producer's risk are presented. Some tables are provided and the results are illustrated by an example of a real data set

    Mode NASA blade used to calculate the power generator for (VAWT) by drag and lift coefficients

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    One of the confrontations with increasing demand on power in the entire world the methodologies of provided power divided into traditional methods against renewable methods. This article presents a simulation model to estimate the integrated power from vertical access wind turbine (VAWT) stages of development of a simulation model of local power supply system (LPSS) with (VAWT). However, wind power is one of the quickest developing advances for the sustainable power age. Disturbingly, in the ongoing years a few instances of corruption on telecommunication systems frameworks have emerged because of the presence of wind ranches, and costly and in fact complex restorative estimations needed. The grade of variation of power verified according to the grid size. The parameters were taken in the study through the preparation of the model are (efficiency, cost, and system response) compared to the benefits against disadvantages when combining the two systems to achieve a high performance of the power stability

    Performance of Teaching and Learning Technology Internship Students as Perceived by Their Trainers

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    The purpose of this descriptive study is to evaluate the performance of teaching and learning technology students of the College of Education, Sultan Qaboos University during their internship experience. Trainers of the interns rated them on 15 items of performance as displayed in the questionnaire of the study. The internal consistency of the questionnaire was significantly high (.96). It was observed that the general level of performance of the interns was high (a mean of 4.40 out of 5) and the ratings of the individual items of performance ranged from 4.04 to 4.59. However, no gender significant differences were observed in the global ratings of males and females. Apart from this, it was found that 2014 cohort interns performed better than earlier cohorts (before 2014).  The study reveals other significant findings such as location of internship (public or private sector) did not affect performance of interns. Similarly, type of institution (educational or non-educational) was not a significant factor of performance, however, interns in non-educational institutions performed better (though not significantly) than interns in educational institutions). Interns with higher GPAs outperformed their colleagues with lower GPAs. Keywords: Internship evaluation, supervisors’ ratings of interns, teaching and learning technolog

    Effect of Corrugation Angle and Direction on the Performance of Corrugated Steel Plate Shear Walls

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    Corrugated steel plate shear wall (CSPSW) is one of the lateral resistance systems which consists mainly of steel frame (beam and column) with vertical or horizontal corrugated steel plate connected to the frame by weld, bolts or both. This type of steel shear wall characterized by low cost and short construction time with high strength, ductility, initial stiffness and excellent ability to dissipate energy. The aim of this paper is to evaluate the effect of corrugation angle and its direction on the performance of CSPSW under cyclic loading. The Finite element analysis was employed to achieve the research aim. The FE models were validated with experimental data available in the literature. Results reveal that the corrugation angle has a clear influence on initial stiffness, strength, ductility, and energy dissipation of CSPSW. The optimum performance of CSPSW can be obtained with angles of 30o for CSPSW with vertical corrugation and 20o for CSPSW with horizontal corrugation. The use of CSPSW with vertical corrugation provides higher strength, stiffness, and ductility compared to CSPSW with horizontal corrugation. Therefore, it is recommended to use CSPSW with vertical corrugation

    Evaluation of Legislation Adequacy in Managing Time and Quality Performance in Iraqi Construction Projects- a Bayesian Decision Tree Approach

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    Delay and quality defects are significant problems in Iraqi construction projects. During the period from 2003-2014, legislation has been changed to enhance the performance of construction project. This change is done by modifying some clauses of legislation and adding or deleting the others. The aim of this study is to evaluate the adequacy of these changes by using questionnaire and Bayesian decision tree model. 30 projects were taken for the period from 2003-2014. Performance of construction project was assessed on one hand by conducting a questionnaire which depend on the impact of legislation clauses on the time and quality performance, while on the other hand Bayesian decision tree model was developed in which qualitative estimate of time and quality performance by using KNIME program. The results of questionnaire estimate the delay from very low to very high and quality from very low to high in Iraqi construction industry. The results of Bayesian decision tree model reveal that the high percentage of construction projects were implemented with very high delay and high level of quality. The model gives good accuracy in prediction time and quality performance about 86.7%. These results show the enhancement in the quality performance is greater than the time performance under the legislative change. The model can assist the Iraqi legislator in evaluation the impact of legislation on time and quality performance of construction project

    Improved integrity constraints checking in distributed databases by exploiting local checking.

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    Most of the previous studies concerning checking the integrity constraints in distributed database derive simplified forms of the initial integrity constraints with the sufficiency property, since the sufficient test is known to be cheaper than the complete test and its initial integrity constraint as it involves less data to be transferred across the network and can always be evaluated at the target site (single site). Their studies are limited as they depend strictly on the assumption that an update operation will be executed at a site where the relation specified in the update operation is located, which is not always true. Hence, the sufficient test, which is proven to be local test by previous study, is no longer appropriate. This paper proposes an approach to checking integrity constraints in a distributed database by utilizing as much as possible the local information stored at the target site. The proposed approach derives support tests as an alternative to the existing complete and sufficient tests proposed by previous researchers with the intention to increase the number of local checking regardless the location of the submitted update operation. Several analyses have been performed to evaluate the proposed approach, and the results show that support tests can benefit the distributed database, where local constraint checking can be achieved

    Bayesian Inference on the Variance of Normal Distribution Using Moving Extremes Ranked Set Sampling

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    Bayesian inference of the variance of the normal distribution is considered using moving extremes ranked set sampling (MERSS) and is compared with the simple random sampling (SRS) method. Generalized maximum likelihood estimators (GMLE), confidence intervals (CI), and different testing hypotheses are considered using simple hypothesis versus simple hypothesis, simple hypothesis versus composite alternative, and composite hypothesis versus composite alternative based on MERSS and compared with SRS. It is shown that modified inferences using MERSS are more efficient than their counterparts based on SRS
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