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Abstract

For the past few decades innovation in construction material has grown a lot. This leads to special concrete such as self-compacting concrete, geopolymer concrete, self-healing concrete, etc. To prepare a special concrete apart from regular concreting material some sort of special materials was also needed, like mineral and chemical admixtures. Hence it is necessary to study the effect of these admixtures in cement paste and mortar before studying the same in concrete. Hence an attempt is made to study the effect of mineral and chemical admixtures in the fresh and hardened properties of cement paste and mortar. For this study ultrafine natural steatite powder is taken as mineral admixture and polycarboxylic based superplasticizer and glenium stream 2 were taken as chemical admixtures. Ultrafine natural steatite powder was used as additive to cement in various percentages like 0%, 5%, 10%, 15%, 20% and 25%. Superplasticizer and viscosity modifying admixture were taken as 1.5% and 0.5%, respectively. Then various combinations were worked out. To study the fresh property of cement paste consistency, initial setting time and miniature slump cone test were done based on the results yield stress of cement paste also calculated empirically. To study the hardened property compression test on cement mortar was done. Based on the test results it is clear that the addition of ultrafine natural steatite powder increases the water demand hence reduces the workability. On the other hand, it increases the compressive strength up to a certain limit. Adding superplasticizer increases the workability and reduces the water demand and viscosity modifying admixture reduces the bleeding and segregation effects hence increases the compressive strength.

Open access

Abstract

Educational data mining is an emerging exquisite field that has been successfully implemented in higher education. One of the best ways to increase the efficiency of this emerging phenomenon is to select efficient professors and effective teaching methods. This study is intended to show academic success factors to have better management in student curriculum, contextualizing the progress and to prevent unfavorable conditions for students. In this research, students of Shahrood University of Technology were studied. Initially, 3,765 samples of students' educational background were considered. Then, pre-processing was performed to make the data normalized. Next, several predictive models were developed using a supervised data mining approach. Next, five algorithms by the best result were selected. Comparing the results of algorithms applied to data, the two algorithms, radial basis function network and the Naïve Bayes with respectively value F-measure 0.929 and 0.942 showed more accurate results. Finally, the most effective feature was selected, the attributes ‘maximum semester’ and ‘the total number of units dropped’ were ranked an the most important, and the three attributes of ‘the basic courses average’, ‘the number of units of main courses’ and ‘the total average’, were placed in the next ranks.

Open access

Abstract

In recent years, managers of both private and public organizations in developing countries have been struggling to double production and improve service delivery in their organizations. Successful organizations in the western world were, however, identified with the use of Information Technology (IT). The paper examined the magnitude of IT and its application in human resource management. Four organizations from private and public sectors were selected from all. Two organizations from each sector, members of staff, Human Resource (HR) professionals and managers of these organizations were targeted. A structured questionnaire was used to collect data from the staff and unstructured interviews were designed to gather data from the HR practitioners and managers of these organizations. A statistical package for social sciences (SPSS) was used to analyse the data. In general, about 76.9% of the participants said that IT application in HR functions enhances organizational productivity. The selected organizations could boast of basic IT facilities, but their numerical strength still remains a challenge especially among organizations in the public sector. Organizations in both sectors must invest more in IT and its related accessories as a means of solving problem of inadequacy. Internet connectivity and company website were lacking in some organizations across both sectors and should be considered so as to improve upon the human resource functions and quality service delivery in the deprived regions of Ghana. Staff motivation, wage and salaries, strategic management and organizational leadership were mentioned as factors when put together with IT would augment productivity in any given economy.

Open access

Abstract

Over the recent years metallic foams have become a popular material due to their unique characteristics like low density coupled with beneficial mechanical properties such as good energy absorption, heat resistance, flame resistance, etc. However, their production processes (foaming) is highly stochastic which results in an inhomogeneous foam structure. Hybrid aluminum foam with closed-cell has been manufactured using direct foaming method coupled with the Taguchi Design of Experiments (DOE). Image analysis has been carried out to determine the average porous area and pore size. The influence of the production parameters (amount of foaming agent added, mixing speed and temperature) on the pore size and the porous area has been analyzed using the statistical Taguchi technique. From the experiments it was seen that the most important control factor for both the pore size and the porous area is the amount of the foaming agent added, followed by temperature and stirring speed. Furthermore, the statistical significance of these manufacturing parameters on the response was also investigated by performing analysis of variance (ANOVA) statistical method.

Open access

Abstract

In this paper the shear resistance of a member without shear reinforcement according to Eurocode 2 is investigated. This expression, as most expressions of design codes typically used to estimate the nominal shear resistance, has been created based on experimental investigations. It will be verified that in case of non-prestressed reinforced concrete member without stirrups, the shear resistance is carried by the shear resistance of the compressive zone; and the shear resistance given by the empirical expression of Eurocode 2 is actually the shear resistance of the compressive zone.

Knowing the mechanical background of the empirical expressions of Eurocode 2, the limits of its applicability can be shown, thus its error can be predicted. Using the reports of experimental investigations, it is easy to find cases to prove the correctness of the error-prediction. In this paper simple modifications will be suggested to Eurocode 2 shear design procedures, by which a more consistent level of safety can be ensured.

Open access

Abstract

Microgrid (MG) is a system of production and distribution of electrical energy that can operate both in grid-connected and islanded modes. This capability leads to significant variations in the fault current level. Moreover, dynamic changes corresponding to the line outage contingencies or outages of the distributed generations (DGs) that are implemented for local generation in the MGs lead to the changes in the fault current level. These changes in the fault current level make some miscoordination between the overcurrent relays (OCRs) in the conventional protection schemes. To overcome this drawback, there is a need for an adaptive protection scheme that can adapt to both operational and dynamic changes and takes effective protection decisions accordingly. This paper first presents a statistic-based review of MG and its protection including total publications, type of publications, the ten most researchers, and the ten most sources. Finally, comprehensive remarks of the 30 most cited papers related to adaptive protection of MG are presented. This paper will help the researchers of the MG protection to learn the most desirable techniques and the concentration of studies in adaptive protection of MGs for future works.

Open access

Abstract

This article contributes a novel technique based on cascade classifiers for smoke detection by utilizing the image processing method. It has been a difficult issue for ten years or so due to its variety in shape, texture, and color. In this article, a machine learning methodology is represented to tackle this issue and simulated with MATLAB software. The smoke detection issue acted like a classification issue. The solution is demonstrated as a binary classification issue. Hence, the support vector machine (SVM) is represented for classification. In order to train and test the SVM classifier, both samples of positive and negative are gathered. Two SVM classifiers are utilized in the cascade. The first classifier distinguishes the presence of smoke if smoke presents in a provided input image; the second classifier is utilized to find the locale of smoke in a provided input image. The size of the window is set to 32 × 32 and slided across the whole image to identify the smoke in a zone of the window. The novel technique is a training dataset and utilizing linear kernel function. In this manner, the novel technique is tested with a test dataset. The first SVM classifier obtained 100% accuracy in training and 96% accuracy in testing. A training accuracy of 96% and a test accuracy of 93.6% were obtained by the second SVM classifier. This novel technique proved to be more proficient and cost-savvy than the traditional strategies.

Open access
International Review of Applied Sciences and Engineering
Authors: Ayad Q. Al-Dujaili, Amjad J. Humaidi, Daniel Augusto Pereira, and Ibraheem Kasim Ibraheem

Abstract

Ball and Beam system is one of the most popular and important laboratory models for teaching control systems. This paper proposes a new control strategy to the position control for the ball and beam system. Firstly, a nonlinear controller is proposed based on the backstepping approach. Secondly, in order to adapt online the dynamic control law, adaptive laws are developed to estimate the uncertain parameters. The stability of the proposed adaptive backstepping controller is proved based on the Lyapunov theorem. Simulated results are presented to illustrate the performance of the proposed approach.

Open access

Abstract

Location specific services are widely used in outdoor environment and their indoor counterpart is gaining more popularity as well. There is no standardized technology exists for indoor localization, usually smart phone is used as a localization platform and the field strength of an existing radio frequency infrastructure is used as the location specific information. Smart devices are also equipped with several sensors capable of capturing the motion data of the device. Detecting the walking step, turn, stairs motion type can refine the indoor position using digital indoor map as a reference. The real-time recognition of the motion type is possible with a precisely constructed and trained convolutional neural network and therefore it can improve the stability of the localization.

Open access

Abstract

Brigittaplatz located in the 20th district of Vienna, which is a mixed culture residential community with various issues. This paper attempts to uncover the existing problems, weaknesses, potential opportunities of the site and explore a set of local interventions to accomplish site regeneration through architectural and landscape measures. Study utilizes two axes to improve and reconnect the public service, green corridor as well as the interactive relationship. All the proposed interventions are not merely public facility renewal but a new functional and social design, which is trying to reactivate the various relationships in the site that can enhance the quality of life and carry over the impact to larger scales. Authors seek a holistic approach to regenerate Brigittaplatz.

Open access