3,025 research outputs found

    Neural Network-Based Approach for Analysis of Rigid Pavement Systems Using Deflection Data

    Get PDF
    This paper focuses on the development of backcalculation models based on artificial neural networks (ANNs) for predicting the layer moduli of the jointed plain concrete pavements, that is, the elastic modulus of the portland cement concrete (PCC) layer and the coefficient of subgrade reaction for the pavement foundation. The ANN-based models were trained to predict the layer moduli by using the falling-weight deflectometer (FWD) deflection basin data and the thickness of the concrete pavement structure. The ISLAB2000 finite element program, extensively tested and validated for more than 20 years, has been employed as an advanced structural model for solving the responses of the rigid pavement systems and generating a knowledge database. ANN-based backcalculation models trained with the results from the ISLAB2000 solutions have been found to be viable alternatives for rapid assessment (capable of analyzing 100,000 FWD deflection profiles in a single second) of the rigid pavement systems. The trained ANN-based models are capable of predicting the concrete pavement parameters with very low

    q-Bernstein polynomials and Bézier curves

    Get PDF
    AbstractWe define q-Bernstein polynomials, which generalize the classical Bernstein polynomials, and show that the difference of two consecutive q-Bernstein polynomials of a function f can be expressed in terms of second-order divided differences of f. It is also shown that the approximation to a convex function by its q-Bernstein polynomials is one sided.A parametric curve is represented using a generalized Bernstein basis and the concept of total positivity is applied to investigate the shape properties of the curve. We study the nature of degree elevation and degree reduction for this basis and show that degree elevation is variation diminishing, as for the classical Bernstein basis

    Uji Adaptasi Teknologi Budidaya Bawang Merah di Kabupaten Enrekang Sulawesi Selatan

    Full text link
    Application of Shallot Cultivation Technology in Enrekang, South Sulawesi. Shallot is one of the important vegetable crops in South Sulawesi, but the level of productivity is still low at 6 t / ha. This is caused partly by the lack of specific location technology. The purpose of the assessment is to to get a package of shallot cultivation technology appropriate and in accordance with local conditions. Assessments conducted at Tominawa Village, Baraka Sub-district, Enrekang District from March to December 2008, using a paired plot design, with two treatments: (1) The application of cultivation technology and (2) Cultivation of farmer ways. The assessment indicated that the application of cultivation technology as recommended giving shallot growth better than the way farmers plant growth. In this treatment of tuber fresh weight per 10 groves of shallots, tubers and higher tuber diameter of each 937 g, 3.86 cm and 4.20 cm. Furthermore, the number of tubers per hill and tuber dry weight per 10 clusters each tuber and 810 g. 7.28 While the yield obtained on the recommendation technology is 2772 kg/ha, equivalent 0.35 7.92 t/ha. Acceptance of farmers on the application of technology recommended treatment is USD. 30,492,000 as of 0.35 ha with RC ratio of 2.45

    Non-Destructive Evaluation of Iowa Pavements Phase 2: Development of a Fully Automated Software System for Rapid Analysis/Processing of the Falling Weight Deflectometer Data

    Get PDF
    The Office of Special Investigations at Iowa Department of Transportation (DOT) collects FWD data on regular basis to evaluate pavement structural conditions. The primary objective of this study was to develop a fully-automated software system for rapid processing of the FWD data along with a user manual. The software system automatically reads the FWD raw data collected by the JILS-20 type FWD machine that Iowa DOT owns, processes and analyzes the collected data with the rapid prediction algorithms developed during the phase I study. This system smoothly integrates the FWD data analysis algorithms and the computer program being used to collect the pavement deflection data. This system can be used to assess pavement condition, estimate remaining pavement life, and eventually help assess pavement rehabilitation strategies by the Iowa DOT pavement management team. This report describes the developed software in detail and can also be used as a user-manual for conducting simulation studies and detailed analyses

    Pengaruh Iklan Dan Harga Terhadap Keputusan Pembelian Handphone Merek Xiomi Pada Ivan Cell Malang (Studi Kasus Pada Konsumen Ivan Cell Malang)

    Get PDF
    ABSTRACTThis study aims to determine the effect of advertising and price on purchasing decisions at Ivan Cell Malang. The sample in this study amounted to 80 respondents.The method used is descriptive data analysis by using the validity, reliability, normality test, multicollinearity test, heterocesdasticity test, multiple linear analysis test, determination coefficient test, f test, and t hypothesis test.The results of descriptive analysis in this study indicate that each variable has an effect on purchasing decisions, namely advertising, price has a positive effect on purchasing decisions. Advertising variables have a significant effect on purchasing decisions at Ivan Cell Malang Stores. Price variables have a significant effect on purchasing decisions at Ivan Cell Malang Stores. Advertising and price simultaneously influence purchasing decisions at Ivan Cell Malang Stores.Keywords: Advertising and Price Against Purchasing Decisions

    Study of Dissimilar Welding AA6061 Aluminium Alloy and AZ31B Magnesium Alloy with ER5356 Filler Using Friction Stir Welding

    Get PDF
    This paper is to study of dissimilar welding AA6061 aluminium alloy and AZ31B magnesium alloy with ER5356 filler using friction stir welding. 2 mm thick plates of aluminium and magnesium were used. Friction stir welding operations were performed at different rotation and travel speeds and used the fixed tilt angle which is 3°. The rotation speeds varied from 800 to 1100 rpm, and the travel speed varied from 80 to 100 mm/min. In the range rotation speed of 800 to 1000 rpm and welding speed of 80 to 100 mm/min there are no defect at the weld. Tensile test show the higher tensile strength is 198 MPa and the welding efficiency is about 76%

    Effect of laser surface modification (LSM) on laser energy absorption for laser brazing

    Get PDF
    Since the development of the laser in the 1960s a rapid development of research interests in science and technology took place. Since then, the need of laser application in industrials such as automotive, aerospace and electronics is increasing because of several advantages like automation worthiness, noncontact processing and product quality improvement. In this present study, the effect of Laser Surface Modification (LSM) on pure copper plate towards the laser energy absorption during indirect laser brazing process was studied. The laser brazing experiment was conducted inside a chamber under controlled vacuum pressure with 400Pa and irradiated with constant 140 Watt laser power. The defocusing features for laser brazing was used in order to find better focal position. Accordingly, the focal length for this laser brazing experiment was set to the focus point at 124 mm from the focal plane. Meanwhile, during LSM process, laser parameters such as laser scanning speed and focus length have been kept constant throughout the surface modification process. Yet, the laser power and laser frequency have been varied from 9 Watt to 27 Watt and 10 kHz to 80 kHz respectively. Apparently, surface roughness due to surface removal and oxide layer formation were presented during LSM process. These two surface integrities were found to be the factors of increasing laser energy absorption. It was discovered that an increase in surface roughness and oxide layer formation can absorb more laser energy which then results an increase in brazing temperature during laser brazing. This is because, increasing surface roughness will scatter the laser energy over a larger surface area, multiply the reflections in the surface irregularities while the oxide layer will enhance the interference phenomena of laser energy occurring inside the oxide layer. Both mechanisms increase laser energy absorptivity during laser brazing which results a high brazing temperature
    corecore