744 research outputs found

    Experimental and Finite Element Analysis of Continuous RC Slab Panels with Steel Fiber Reinforced Concrete (SFRC) as an Alternative to Negative Reinforcement

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    This paper presents experimental and finite element analysis of RC slab panels with steel fiber reinforced concrete (SFRC). For this purpose, four SFRC slab panels with (2000×250×50mm) dimensions are poured using a concrete class of (f'c=22MPa) with (15kg/m3) dosage of steel fibers and steel class (fy=410MPa) without shear stirrups. Two of the slab panels were modeled by using nonlinear material properties adopted from experimental study and analyzed till the ultimate failure by ANSYS (Version-15) software. The tested slab panels are subjected to bending by two-point loading, exactly after having been moist-cured for (28 days). The slab panels were tested up to the failure with control of loads. The applied loads and mid-span deflections are carefully recorded at every (5kN) load increment from the beginning till the ultimate failure. The results obtained from the finite element and experimental analyses are compared to each other. It is seen from the results that the finite element failure behavior indicates a good agreement with the experimental failure behavior. The paper concludes that the traditional negative steel reinforcement (steel bars) can be replaced (partially or totally) by using the adopted technique and the contribution of SFRC in manufacturing of thin slabs panels was enhanced. Keywords: Finite Element, Steel fiber, Continuous Slab, Concrete, NSC, Ansys. DOI: 10.7176/CER/11-3-01 Publication date: April 30th 201

    Biomedical, Industrial & Human Factors Engineering Academic Program Review, 2014

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    This 30 page report reviews several programs from Wright State University\u27s Department of Biomedical, Industrial & Human Factors Engineering , specifically looking at the time from Fall 2009 to Fall 2014. Programs Reviewed: Biomedical Engineering Industrial & Systems Engineering Industrial & Human Factors Engineering Lean Ergonomics for Manufacturing and Healthcar

    New Hybrid Data Preprocessing Technique for Highly Imbalanced Dataset

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    One of the most challenging problems in the real-world dataset is the rising numbers of imbalanced data. The fact that the ratio of the majorities is higher than the minorities will lead to misleading results as conventional machine learning algorithms were designed on the assumption of equal class distribution. The purpose of this study is to build a hybrid data preprocessing approach to deal with the class imbalance issue by applying resampling approaches and CSL for fraud detection using a real-world dataset. The proposed hybrid approach consists of two steps in which the first step is to compare several resampling approaches to find the optimum technique with the highest performance in the validation set. While the second method used CSL with optimal weight ratio on the resampled data from the first step. The hybrid technique was found to have a positive impact of 0.987, 0.974, 0.847, 0.853 F2-measure for RF, DT, XGBOOST and LGBM, respectively. Additionally, relative to the conventional methods, it obtained the highest performance for prediction

    An adaptive discrete cosine transform coding scheme for digital x-ray images

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    The ongoing development of storage devices and technologies for medical image management has led to a growth in the digital archiving of these images. The characteristics of medical x-rays are examined, and a number of digital coding methods are considered. An investigation of several fast cosine transform algorithms is carried out. An adaptive cosine transform coding technique is implemented which produces good quality images using bit rates lower than 0.38 bits per picture elemen

    Space station automation of common module power management and distribution

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    The purpose is to automate a breadboard level Power Management and Distribution (PMAD) system which possesses many functional characteristics of a specified Space Station power system. The automation system was built upon 20 kHz ac source with redundancy of the power buses. There are two power distribution control units which furnish power to six load centers which in turn enable load circuits based upon a system generated schedule. The progress in building this specified autonomous system is described. Automation of Space Station Module PMAD was accomplished by segmenting the complete task in the following four independent tasks: (1) develop a detailed approach for PMAD automation; (2) define the software and hardware elements of automation; (3) develop the automation system for the PMAD breadboard; and (4) select an appropriate host processing environment

    The design and performance of pressure pipe liners under static and cyclic loading

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    Cured-in-place pipe (CIPP), is a widely used trenchless technology. Based on the current liner design method, American Society for Testing and Materials (ASTM) F2207-02, several aspects are studied for the effect on estimating the long-term performance of the liners. While estimating the liner burst pressure, the effect from host pipe material properties, liner material properties, defect geometry, liner creep properties and loading condition should be considered. The burst pressure calculated based on the existing method is overestimated and this allows an increased risk of structural failure before the expected design life is reached. Compared with cast-iron, a PVC host pipe provides less constraint for the liner and causes a lower liner burst pressure. The existing method is safe to calculate the liner burst pressure when the defect size is at the high end of the range of defect sizes in comparison with the host pipe size. When the defect size decreases, the estimate becomes less safe. To maintain the same safety factor, a correction should be applied to reduce the estimated liner burst pressure. To estimate the liner burst pressure for defect shapes other than square and circular, the defect area should be measured and transformed to a square shape with same area. Based on the length of the square, the ASTM method can be used to calculate the liner burst pressure. It is also recommended to use different correction factors based on the extension direction of the defect. The creep property of the liner is not an ignorable factor. The displacement could increase about 100% due to the creep effect. A cyclic loading condition shows a noticeable effect on the development of displacement and strain. The strain development shows that a liner\u27s Young\u27s Modulus gradually decreases under a cyclic loading condition. This means that a liner could fail under a cyclic loading condition at a lower pressure level. Based on this research, correction factors, according to each of the different aspects of liner behavior outlined above, are recommended for estimating an appropriate liner burst pressure. Recommendations for further research are also provided

    Social-aware hybrid mobile offloading

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    Mobile offloading is a promising technique to aid the constrained resources of a mobile device. By offloading a computational task, a device can save energy and increase the performance of the mobile applications. Unfortunately, in existing offloading systems, the opportunistic moments to offload a task are often sporadic and short-lived. We overcome this problem by proposing a social-aware hybrid offloading system (HyMobi), which increases the spectrum of offloading opportunities. As a mobile device is always co- located to at least one source of network infrastructure throughout of the day, by merging cloudlet, device-to-device and remote cloud offloading, we increase the availability of offloading support. Integrating these systems is not trivial. In order to keep such coupling, a strong social catalyst is required to foster user's participation and collaboration. Thus, we equip our system with an incentive mechanism based on credit and reputation, which exploits users' social aspects to create offload communities. We evaluate our system under controlled and in-the-wild scenarios. With credit, it is possible for a device to create opportunistic moments based on user's present need. As a result, we extended the widely used opportunistic model with a long-term perspective that significantly improves the offloading process and encourages unsupervised offloading adoption in the wild

    Laser application to measure vertical sea temperature and turbidity, design phase

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    An experiment to test a new method was designed, using backscattered radiation from a laser beam to measure oceanographic parameters in a fraction of a second. Tyndall, Rayleigh, Brillouin, and Raman scattering all are utilized to evaluate the parameters. A beam from a continuous argon ion laser is used together with an interferometer and interference filters to gather the information. The results are checked by direct measurements. Future shipboard and airborne experiments are described

    Fiscal year 1973 scientific and technical reports, articles, papers, and presentations

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    Formal NASA technical reports, papers published in technical journals, and presentations by MSFC personnel in FY73 are presented. Papers of MSFC contractors are also included
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