Search results for " Modeling"
showing 10 items of 2411 documents
Unified Modeling Language
2005
Mature engineering disciplines are generally characterized by accepted methodical standards for describing all relevant artifacts of their subject matter. Such standards not only enable practitioners to collaborate, but they also contribute to the development of the whole discipline. In 1994, Grady Booch, Jim Rumbaugh, and Ivar Jacobson joined together to unify the plethora of existing object-oriented systems engineering approaches at semantic and notation level (Booch, 2002; Fowler, 2004; Rumbaugh, Jacobson, & Booch, 1998). Their effort led to the Unified Modeling Language (UML), a well-known, general-purpose, tool-supported, process-independent, and industry-standardized modeling lang…
Automatic Reengineering in MDA Using Rewriting Logic as Transformation Engine
2005
Legacy systems are information systems that have been developed by means of methods, tools and database management systems that have become obsolete, but they are still being used due to their reliability. As time goes on, the maintenance of this software becomes more complex, expensive and painful. The MOMENT framework supports automatic formal model transformations in MDA. This model transformation approach is based on the algebraic specification of models and benefits from mature term rewriting system technology to perform model transformation using rewriting logic. In this paper, we present how we apply this formal transformation mechanism to recover a legacy relational database, obtain…
The use of soil water retention curve models in analyzing slope stability in differently structured soils
2017
Abstract This study analyzes whether and at what rate the parameterization of the Soil Water Retention Curve (SWRC) affects the analysis of shallow slope stability for differently structured unsaturated soils. Advanced empirical or physically-based equations of SWRCs have been proposed in literature to describe soil systems characterized by the so-called bimodal porous domain. In unsaturated soils, SWRC affects the stability assessment in two ways. It influences the resistance properties in terms of shear strengths, which depend on the soil water suction; and it affects the hydrological process modeling (e.g. infiltration) directly influencing soil moisture patterns and indirectly influenci…
Immagine urbana e qualità dello spazio nel rilievo tridimensionale di due borgate storiche palermitane
2014
Lo sviluppo dei software di rappresentazione digitale ha comportato una significativa evo- luzione dei modelli rappresentativi, aprendo contemporaneamente la strada a nuove que- stioni di natura non soltanto operativa, ma anche sostanziale. L’assenza di scala di riduzione, la tridimensionalità in “real time”, l’immersività e l’interattività dello spazio virtuale sono infatti ben più di semplici novità strumentali: si pongono come nuovi codici, introducono una visibilità simultanea e onnicomprensiva, definiscono il modello che si viene a elaborare come un “alter” dello spazio indagato, autonomo e parallelo alla realtà stessa, ben più insomma del ruolo di “model- lo” del reale al quale la rap…
Urban runoff modelling uncertainty: Comparison among Bayesian and pseudo-Bayesian methods
2009
Urban stormwater quality modelling plays a central role in evaluation of the quality of the receiving water body. However, the complexity of the physical processes that must be simulated and the limited amount of data available for calibration may lead to high uncertainty in the model results. This study was conducted to assess modelling uncertainty associated with catchment surface pollution evaluation. Eight models were compared based on the results of a case study in which there was limited data available for calibration. Uncertainty analysis was then conducted using three different methods: the Bayesian Monte Carlo method, the GLUE pseudo-Bayesian method and the GLUE method revised by m…
A data-logging mechanism to support e-learning systems
2015
User profiling and e-learning have received great attention in the last years. In a learning environment, user profiling provides historical data of the students' performance on different learning subjects. e-Learning tools such as serious games can collect user's data and build a user profile by appropriate storing these information. Thus, by combining above techniques and analysing each user's data a teacher can provide personalized treatment to her/his students. In this paper we present our solution on storing and analysing user data on a centralized server. Our system stores data collected from users with dyslexia. We maintain one user profile per student from data taken from a) user re…
Further results on mathematical models of vehicle localized impact
2010
Accepted version of an article published by IEEE. (c) 2010 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works Published version:http://dx.doi.org/10.1109/ISSCAA.2010.5634041 In this paper, we propose a method of modeling for vehicle crash systems based on viscous and elastic properties of the materials. This paper covers an influence of different arrangement of spring and damper on the models? respons…
Investigation of vehicle crash modeling techniques: theory and application
2013
Published version of an article in the journal: The International Journal of Advanced Manufacturing Technology. Also available from the publisher at: http://dx.doi.org/10.1007/s00170-013-5320-3 Creating a mathematical model of a vehicle crash is a task which involves considerations and analysis of different areas which need to be addressed because of the mathematical complexity of a crash event representation. Therefore, to simplify the analysis and enhance the modeling process, in this work, a brief overview of different vehicle crash modeling methodologies is proposed. The acceleration of a colliding vehicle is measured in its center of gravity—this crash pulse contains detailed informati…
The performance investigation of viscoelastic hybrid models in vehicle crash event representation
2011
Aurthor's version of a chapter published in the book: Proceedings of the 18th IFAC World Congress 2011. Also available from the publisher at: http://dx.doi.org/10.3182/20110828-6-IT-1002.00284 This paper presents application of physical models composed of springs, dampers and masses joined together in various arrangements to simulation of a real car collision with a rigid pole. Equations of motion of those systems are being established and subsequently solutions to obtained differential equations are formulated. We start with a general model consisting of two masses, two springs, and two dampers, and illustrate its application to represent fore-frame and aft-frame of a vehicle. Hybrid model…
Landing gear suspension control through adaptive backstepping techniques with H∞ performance
2011
Author's version of a chapter published in the book: Proceedings of the 18th IFAC World Congress 2011. Also available from the publisher at: http://dx.doi.org/10.3182/20110828-6-IT-1002.00589 Landing gear suspension systems fulfill the tasks of absorbing the vertical energy of the touch-down as well as providing passenger and crew comfort with a smooth ground ride before take-off and after landing. They are also designed to have optimal performance in the case of a hard landing. In general, the tasks of aircraft landing gears are complex and sometimes lead to a number of contradictory requirements. Although there are existing modifications of aircraft shock absorbers to reduce the problem, …