Nokia Research Center (NRC) has been leading Esprit project ARES (Architectural Reasoning for Embedded systems) for two years. One of the main purposes of ARES is to demonstrate the use of architectural modeling in co...
详细信息
Nokia Research Center (NRC) has been leading Esprit project ARES (Architectural Reasoning for Embedded systems) for two years. One of the main purposes of ARES is to demonstrate the use of architectural modeling in controlling properties of industrial scale products and product families. Two examples are documented. Forward architecting was applied in modelingthe new architecture for our mobile phone family showing how to control the dynamic properties of the software. Reverse architecting was used to tune the performance of our telephone switch software. Both cases show that special purpose models can be constructed even for very large systems and they do give valuable insight to the properties of the software.
Local maxima in linear underdetermined inverse tomographies for EEG may be useful for initializing nonlinear overdetermined localization of multiple dipoles. the feasibility of this suggestion is studied by applying f...
详细信息
Local maxima in linear underdetermined inverse tomographies for EEG may be useful for initializing nonlinear overdetermined localization of multiple dipoles. the feasibility of this suggestion is studied by applying four distributed inverse approaches (MUSIC and three types of minimum norm) to a large number of simulated dipole configurations. A variant of LORETA with monopolar (i.e., reciprocal distance) smoothing is implemented, and a new minimum norm with directional dipolar smoothing is introduced.
Brain source localization is an important inverse problem for brain diagnosis and functional analysis. the usefulness of BPNN (back propagation neural network) to solve this problem has been reported. the purpose of t...
详细信息
Brain source localization is an important inverse problem for brain diagnosis and functional analysis. the usefulness of BPNN (back propagation neural network) to solve this problem has been reported. the purpose of the study is to examine the practical effectiveness of NN for single dipole source localization from EEG based on conventional 18 electrodes of a 10-20system, and to investigate estimation accuracy in relation to EEG references, dipole positions and network training.
the design, implementation, and testing of virtual environments is complicated by the concurrency and real-time features of these systems. therefore, the development of formal methods for modeling and analysis of virt...
详细信息
the design, implementation, and testing of virtual environments is complicated by the concurrency and real-time features of these systems. therefore, the development of formal methods for modeling and analysis of virtual environments is highly desirable. In the past, Petri net models have led to good empirical results in the automatic verification of concurrent and real-time systems. We applied a timed extension of Petri nets to modeling and analysis of the CAVE/sup TM/ virtual environment at the University of Illinois at Chicago. We report on our time Petri net model and on empirical studies that we conducted withthe Cabernet toolset from Politecnico di Milano. Our experiments uncovered a flaw in the way a shared buffer is used by CAVE processes. Due to an erroneous synchronization on the buffer, different CAVE walls can simultaneously display images based on different input information. We conclude from our empirical studies that Petri net-based tools can effectively support the development of reliable virtual environments.
Software architecture descriptions are high-level models of software systems. Some researchers have proposed special-purpose architectural notations that have a great deal of expressive power but are not well integrat...
详细信息
Software architecture descriptions are high-level models of software systems. Some researchers have proposed special-purpose architectural notations that have a great deal of expressive power but are not well integrated with common development methods. Others have used mainstream development methods that are accessible to developers, but lack semantics needed for extensive analysis. We describe an approach to combining the advantages of these two ways of modeling architectures. We present two examples of extending UML, an emerging standard design notation, for use with two architecture description languages, C2 and Wright. Our approach suggests a practical strategy for bringing architectural modeling into wider use, namely by incorporating substantial elements of architectural models into a standard design method.
A parasitic antenna model of a human body exposed to the ELF electromagnetic field is proposed. the human body is, in accordance with wire antenna theory, represented by a cylindrical monopole antenna located vertical...
详细信息
A parasitic antenna model of a human body exposed to the ELF electromagnetic field is proposed. the human body is, in accordance with wire antenna theory, represented by a cylindrical monopole antenna located vertically over perfect ground. the analysis is performed by solving the corresponding Pocklington integral equation by means of the boundary element method. Numerical results are presented for the current distribution induced in a human body standing on the perfect ground near a three phase power line.
Symbolic computation has been applied to the design procedure for blood glucose control of diabetic patients under intensive care. To design the multivariable modal control system based on nonlinear state-space model ...
详细信息
Symbolic computation has been applied to the design procedure for blood glucose control of diabetic patients under intensive care. To design the multivariable modal control system based on nonlinear state-space model fully symbolically, MAPLE packages were employed. the model has been verified and tested in a clinical environment.
Heart rate variability (HRV) provides a noninvasive means of quantifying cardiac autonomic activity. Imbalances in autonomic activity between the sympathetic and parasympathetic systems accompany a number of cardiac d...
详细信息
Heart rate variability (HRV) provides a noninvasive means of quantifying cardiac autonomic activity. Imbalances in autonomic activity between the sympathetic and parasympathetic systems accompany a number of cardiac disorders. this paper provides new results in mathematically modelingthe cardiac nervous system responsible for fluctuations in heart rate. these results clearly demonstrate the differing varieties of heart rate fluctuations over a wide range of cardiac autonomic balances as evidenced by Poincare plots of simulated data vs. actual data obtained from subjects.
In this work, an integral pulse frequency modulation(IPFM) model for physiological systems is studied from the viewpoint of nonlinear dynamics. Rich dynamical structures were found from the model while some model para...
详细信息
In this work, an integral pulse frequency modulation(IPFM) model for physiological systems is studied from the viewpoint of nonlinear dynamics. Rich dynamical structures were found from the model while some model parameters varied, and five features including fix points, periods, bifurcations, period-three windows and quasi-periodicity were observed in the study. Because period-three windows in nonlinear systems are associated with chaos, it is postulated that chaos may occur in this IPFM system at some values of model parameters. the IPFM model has been used for modeling some physiological phenomena, and the results of this work will be useful in understanding the mechanism of physiological rhythm and in explaining some dynamical diseases in the human body.
暂无评论