DSSynth: An automated digital controller synthesis tool for physical plants

We present an automated MATLAB Toolbox, named DSSynth (Digital-System Synthesizer), to synthesize sound digital controllers for physical plants that are represented as linear time-invariant systems with single input and output. In particular, DSSynth synthesizes digital controllers that are sound w.r.t. stability and safety specifications. DSSynth considers the complete range of approximations, including time discretization, quantization effects and finite-precision arithmetic (and its rounding errors). We demonstrate the practical value of this toolbox by automatically synthesizing stable and safe controllers for intricate physical plant models from the digital control literature. The resulting toolbox enables the application of program synthesis to real-world control engineering problems

Técnica Automatizada para Inspeção de Aplicações Web

A aceitabilidade das aplicações Web por seus usuários depende diretamente da usabilidade da aplicação, que pode ser melhorada através da realização de inspeções. Este projeto de pesquisa propõe a evolução de uma técnica de inspeção de usabilidade e a criação de um assistente automatizado de apoio a esta técnica, visando facilitar a adoção da mesma por inspetores com pouca experiência em avaliações de usabilidade.CNP

How to Justify Purchase of an iPad: Users of the Latest Launch

Contemporary technology innovation is increasingly based on convergence and the multiple uses of products. This change is detailed in the literature about new product development, as well as that on systems integration. This article focuses on the factors that determine the justification for using advanced technology products in which the perceived value of the product is not based on its functionality, as much as on its hedonistic or social value as an “all-in-one” product. In this study, consumer behaviors toward the Apple iPad are analyzed using netnographic evidence taken from internet postings by the consumers themselves. Since Apple initially marketed the iPad as a revolutionary product, with integrated services and features, our analysis concentrates on how consumers perceived these new, innovative features, in an effort to justify their purchase of the product. Our findings indicate that consumers’ justifications are based not only on the iPad’s functionality, but also its hedonic traits, and its similarity to the previously released innovative product, the iPhone

Verifying Fragility in Digital Systems with Uncertainties using DSVerifier v2.0

Experimental Setup: The experiments were executed in a computer with the following hardware configurations: Intel Core i7-2600 3.40 GHz processor, 24 GB of RAM, and Ubuntu 64-bits OS. The experiments used the Linux times command to measure CPU time used for each benchmark. The runtime was limited to one hour (i.e., 3600s). Benchmarks Description: IEEE Transaction on Computers Benchmarks: We extracted 4 digital systems (controller and plant) from Keel, L.H. and Bhattacharyya, S.P. 1997. Robust, fragile, or optimal? IEEE Trans. Automat. Control, 42, 1098–1105. All digital systems are designed in transfer-function format, and the discretized plant and controller are published by Bessa, I. V. et al. Formal Non-Fragile Stability Verification of Digital Control Systems with Uncertainty. In IEEE Transactions on Computers, v.66(3), pp. 545-552, 2017. ACM International Conference on Hybrid Systems: Computation and Control (HSCC) Benchmarks: The first set of benchmarks uses the discrete model of a cruise control system for a car, and accounts for rolling friction, aerodynamic drag, and the gravitational disturbance force. The second set of benchmarks considers the discrete model of a simple spring-mass damper plant. A third set of benchmarks uses the discrete model for satellite attitude dynamics, which require attitude control for orientation of antennas and sensors w.r.t. Earth. The fourth and fifth set of benchmarks describe the discrete model of a DC servo motor velocity dynamics. The sixth set of benchmarks contains a well-studied discrete non-minimal phase model. Non-minimal phase models cause additional difficulties for the design of stable controllers. The seventh set of benchmarks describes the discrete model for the Helicopter Longitudinal Motion, which provides the longitudinal motion dynamics of a helicopter. The eighth set of benchmarks contains the discrete model for the known Inverted Pendulum, which describes a pendulum dynamics with its center of mass above its pivot point. The ninth set of benchmarks contains the Magnetic Suspension discrete model, which describes the dynamics of a mass that levitates with support only of a magnetic field. The last set of benchmarks contains the Computer Tape Driver discrete model, which describes a system to read and write data on a storage device. Results: https://docs.google.com/spreadsheets/d/e/2PACX-1vRQDfOY26IHw4gxQFDaRbWVYm-bN4hGOo8d6VZCWiVjSG_nj7qGa6CyDm4phgL97WZNmeXvH-hodhNP/pubhtml