Search results for "Variable"
showing 10 items of 1674 documents
Feature Selection Approach based on Mutual Information and Partial Least Squares
2014
Feature selection technology can improve the modeling accuracy and reduce model’s complexity, especially for the high dimensional spectral data. Aim at this problem, feature selection approach based on mutual information (MI) and partial least square (PLS) is proposed in this paper. MI values between features and responsible variable are calculated, and the threshold value using to select final features is optimal selected based on PLS algorithm. The numbers of the latent values of the PLS and the threshold value of MI are selected according the modeling performance simultaneously. The experimental results based on the near-infrared spectrum show that the proposed approach has better perfor…
Tracking control of network distributed systems in presence of variable time delay and loss of information
2006
This paper deals with the control of network distributed systems which has been at the centre of interest in a wide area of research in the last few year. The control of such systems is very difficult because the communication networks inevitably introduce variable time delays and possible lost of samples. In particular, it is proposed an extension of the approach, derived in the contest of the optimal stochastic regulator problem [1], [2], to the remote tracking problem considering a distributed control system in which the signals from the transducers to the controller and from the controller to the actuator are transmitted through a communication network with variable delays and possible …
PV modules with variable ideality factors
2012
The classical single-exponential I–V curve model for crystalline-Si PV devices assumes a constant ideality factor. The model is widely applied in e.g. modeling the power output of PV systems at different irradiances and temperatures, and also in calculating the Equivalent Cell Temperature (ECT) from the open-circuit voltage. The present paper presents results from several crystalline-Si (c-Si) module types suggesting that the ideality factor may change with irradiance. The possible implications of such variability are discussed, in particular the need for a new ECT calculation procedure as well as for revision of some PV performance models.
Serious Games for Elderly Continuous Monitoring
2014
Information technology (IT) and serious games allow older population to remain independent for longer. Hence, when designing technology for this population, developmental changes, such as attention and/or perception, should be considered. For instance, a crucial developmental change has been related to cognitive speed in terms of reaction time (RT). However, this variable presents a skewed distribution that difficult data analysis. An alternative strategy is to characterize the data to an ex-Gaussian function. Furthermore, this procedure provides different parameters that have been related to underlying cognitive processes in the literature. Another issue to be considered is the optimal dat…
Two-variable First-Order Logic with Counting in Forests
2018
We consider an extension of two-variable, first-order logic with counting quantifiers and arbitrarily many unary and binary predicates, in which one distinguished predicate is interpreted as the mother-daughter relation in an unranked forest. We show that both the finite satisfiability and the general satisfiability problems for the extended logic are decidable in NExpTime. We also show that the decision procedure for finite satisfiability can be extended to the logic where two distinguished predicates are interpreted as the mother-daughter relations in two independent forests.
Traffic management and user perception: an analysis of Variable Message Signs using Fuzzy Logic
2009
Variable message signs have today become an indispensable tool for managing traffic in urban and suburban areas, such as sending real-time information to motorists in transit along roads where panels are positioned. The study draws on drivers’ response to a series of interviews conducted in the city of Brescia. The interviews showed that a large proportion of drivers does not read the messages, and indeed very often does not even remember having seeing the sign. The marginal usefulness of these facilities can probably be attributed to the fact that the panels are constantly used to display messages devoid of immediate interest (eg, greetings, penalties for traffic violations, general inform…
A discontinuous Galerkin formulation for variable angle tow composite plates higher-order theories
2020
A discontinuous Galerkin formulation for the mechanical behaviour of Variable Angle Tow multi-layered composite plates is presented. The starting point of the formulation is the strong form of the governing equations, which are obtained by means of the Principle of Virtual Displacement, the Generalized Unified Formulation and the Equivalent Single Layer assumption for the mechanical behaviour of the whole assembly. To obtain the corresponding discontinuous Galerkin formulation, an auxiliary flux variable is introduced and the governing equations are rewritten as a first-order system of partial differential equations. To link neighbouring mesh elements, suitably defined numerical fluxes are …
Modeling of Friction Losses in Offshore Knuckle Boom Crane Winch System
2018
This paper presents a method for friction modeling in a hydraulically actuated multi motor winch system of an offshore knuckle boom crane. The method is based on a combination of a model of the variable displacement axial piston motor based on measurements from the sub supplier, and combined with a model of the remaining friction loss obtained from measurements on the full system.
One-dimensional nonlinear boundary value problems with variable exponent
2018
In this paper, a class of nonlinear differential boundary value problems with variable exponent is investigated. The existence of at least one non-zero solution is established, without assuming on the nonlinear term any condition either at zero or at infinity. The approach is developed within the framework of the Orlicz-Sobolev spaces with variable exponent and it is based on a local minimum theorem for differentiable functions.