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Results 1091-1100 of 2278 (Search time: 0.007 seconds).
    • Marketing Management and Communications in the Public Sector
    Authors: Martial, Pasquier,; Jean-Patrick, Villeneuve;  Advisor: -;  Co-Author: - (2018)

    Public management and marketing, marketing and Public marketing, basic marketing concept, marketing information research, marketing strategy, marketing instruments, Public communications - an introduction, communications models and strategies, communications instruments, communications control, crisis communications.
    • Online payment fraud: from anomaly detection to risk management
    Authors: Paolo, Vanini; Sebastiano, Rossi; Ermin, Zvizdic;  Advisor: -;  Co-Author: - (2023)

    Online banking fraud occurs whenever a criminal can seize accounts and transfer funds from an individual’s online bank account. Successfully preventing this requires the detection of as many fraudsters as possible, without producing too many false alarms. This is a challenge for machine learning owing to the extremely imbalanced data and complexity of fraud. In addition, classical machine learning methods must be extended, minimizing expected financial losses. Finally, fraud can only be combated systematically and economically if the risks and costs in payment channels are known.
    • rDSA : an intelligent tool for data science assignments
    Authors: Pierpaolo, Vittorini; Alessandra, Galassi;  Advisor: -;  Co-Author: - (2023)

    Tools supporting the teaching and learning of programming may help professors in correcting assignments and students in receiving immediate feedback, thus improving the solution before the final submission. This paper describes the rDSA tool, which was designed, developed, and evaluated to support students in completing assignments concerning (i) the execution of statistical analyses in the R language and (ii) commenting on the results in natural language.
    • Effect of functional groups on tribological properties of lubricants and mechanism investigation
    Authors: Hongxiang, Yu; Haijie, Chen; Zhiwen, Zheng;  Advisor: -;  Co-Author: - (2022)

    Nine organic compounds were utilized as model lubricants to investigate the impact of functional groups on tribological performances. Nonanoic Acid with carboxyl showed the best lubrication properties, and fluid film and tribofilm were coexistent in its friction test, bringing a low friction coefficient and wear rate. In addition, the lubricant with low friction coefficient corresponded to high adsorption energy in density functional theory (DFT) calculations. And the lubricant forming adsorption film with large surface energy displayed small wear rate in friction test.
    • Approximating piecewise nonlinearities in dynamic systems with sigmoid functions: advantages and limitations
    Authors: Cristiano, Martinelli; Andrea, Coraddu; Andrea, Cammarano;  Advisor: -;  Co-Author: - (2023)

    In the industry field, the increasingly stringent requirements of lightweight structures are exposing the ultimately nonlinear nature of mechanical systems. This is extremely true for systems with moving parts and loose fixtures which show piecewise stiffness behaviours. Nevertheless, the numerical solution of systems with ideal piecewise mathematical characteristics is associated with time-consuming procedures and a high computational burden. Smoothing functions can conveniently simplify the mathematical form of such systems, but little research has been carried out to evaluate their effect on the mechanical response of multi-degree-of-freedom systems.
    • Image processing based horizon sensor for estimating the orientation of sounding rockets, launch vehicles and spacecraft
    Authors: Benjamin, Braun; Jochen, Barf;  Advisor: -;  Co-Author: - (2022)

    The paper describes how the attitude of a sounding rocket, launch vehicle or satellite with respect to the Earth can be estimated from camera images of the Earth horizon. Details about detecting the horizon in the camera image, fitting hyperbolae or ellipses to the detected horizon curve and deriving the Earth nadir vector and the corresponding error covariance from the fitted conic section are given. The presented method works at low heights, where the projected horizon mostly appears to be hyperbolic, as well as at large heights, where the projected horizon mostly appears to be elliptic and it is irrelevant if the Earth is fully or only partially in the field of view of the camera.
    • Simultaneous densification and improvement of cold spray additively manufactured Ti-6Al-4 V properties via electro-plastic treatment
    Authors: Mohammed Abdul, Khalik; Saden H., Zahiri; Syed H., Masood;  Advisor: -;  Co-Author: - (2023)

    Large-scale industrial application of additively manufactured (AM) components in general, and specifically cold sprayed additive manufactured (CSAM), is limited due to the nature of this technology and the resulting product’s porosity and embrittlement. To improve the final properties of additively manufactured material, many lengthy, complex, or expensive post-treatments have been proposed. Reducing the environmental impact, cost, and time required for additive manufacturing will allow for greater use in industrial applications. A novel thermomechanical treatment known as in situ electro-plastic treatment (ISEPT) is used in this study to treat CSAM Ti-6Al-4 V alloy known as grade 5 titanium.
    • Combined effect of the interlayer temperature with travel speed on features of thin wall WAAM under two cooling approaches
    Authors: Felipe Ribeiro, Teixeira; Fernando Matos, Scotti; Vinicius Lemes, Jorge;  Advisor: -;  Co-Author: - (2023)

    This work presents the evaluation of the interlayer temperature (IT) with travel speed (TS) combined effect for a given wire feed speed (WFS) on operational, geometrical, and metallurgical features of thin walls with the same width deposited by wire arc additive manufacturing (WAAM) with a low alloy steel, using or not active cooling. A preliminary experimental design was carried out to define a range of IT that could prevent the molten pool from running down and, then, be used in the main experimental design. The main tests were planned and performed to find different IT and TS combinations for a given WFS capable of depositing walls with the same target effective wall width. After selecting the parameters, six walls were deposited, three under natural cooling (NC) and three under ...
    • Strong dependency of the tribological behavior of CuZr-based bulk metallic glasses on relative humidity in ambient air
    Authors: Solène, Barlemont; Paul, Laffont; Rémi, Daudin;  Advisor: -;  Co-Author: - (2023)

    Thanks to their outstanding mechanical properties, Bulk Metallic Glasses (BMGs) are new alternatives to traditional crystalline metals for mechanical and micromechanical applications including power transmission. However, the tribological properties of BMGs are still poorly understood, mostly because their amorphous nature induces counter intuitive responses to friction and wear. In the present study, four different BMGs (Cu47Zr46Al7, Zr46Cu45Al7Nb2, Zr60Cu28Al12, and Zr61Cu25Al12Ti2) underwent ball-on-disc friction tests against 100Cr6 steel balls (American Iron and Steel Institute (AISI) 52100) at different relative humidities (RHs) ranging from 20% to 80%.