Complex real world systems are currently developing to become a decisive instrument for IT-supported problem solving of a great number of problems posed by science, economy and society. By this, we for the first time ...
详细信息
Complex real world systems are currently developing to become a decisive instrument for IT-supported problem solving of a great number of problems posed by science, economy and society. By this, we for the first time face the chance of being able to find new solutions, visions, and strategies for sustainable development on the basis of complex, real world simulations. M3-Simulations is a simulation approach that actively involves man in a simulated world based on scientifically-founded simulation models driven by current data of measurement. This new kind of simulation concept combines reality-based modeling of scientific simulation systems with the intuitive graphic representation, complex communication and interaction structures of virtual worlds in order to support the process of investigation into the possibilities of sustainable development.
We present a method for the analysis of non-stationary time series from dynamical systems that switch between multiple operating modes. In contrast to other approaches, our method processes the data incrementally and ...
详细信息
We present a method for the analysis of non-stationary time series from dynamical systems that switch between multiple operating modes. In contrast to other approaches, our method processes the data incrementally and without any training of internal parameters. It straightaway performs an unsupervised segmentation and classification of the data on-the-fly. In many cases it even allows to process incoming data in real-time. The main idea of the approach is to track and segment changes of the probability density of the data in a sliding window on the incoming data stream. An application to a switching dynamical system demonstrates the potential usefulness of the algorithm in a broad range of applications.
作者：
Hannebauer, MarkusPlanning and Optimization Laboratory
Research Institute for Computer Architecture and Software Technology (FIRST) GMD — German National Research Center for Information Technology eMail: hannebau@first.gmd.de
Several interesting practical problems in process control, planning and scheduling can be expressed and solved using the model of constraint satisfaction problems. At least four drawbacks of this classical model direc...
详细信息
Several interesting practical problems in process control, planning and scheduling can be expressed and solved using the model of constraint satisfaction problems. At least four drawbacks of this classical model directly relate to areas of distribution: complexity, scalability, privacy and robustness. Hence, research on distributed constraint satisfaction problems is a new direction in the area of multi-agent systems. A typical engineering task in distributed constraint satisfaction is the design of the distribution itself. A careful look at this task reveals that the design of distribution is critical to the quality and efficiency of the problem solving process and is itself an optimization problem. In this article we formalize different variants of this configuration problem and prove them to be all at least N P-complete. For solving these problems, we present two local operators, agent melting and agent splitting, that can be combined to allow for an autonomous and dynamic reconfiguration of the organizational structure of the problem-solving agents. We prove sequences of these operators to be sufficient for solving any given configuration problem. We also briefly describe what practical steps are necessary to exploit the rather theoretical result of the proof in realistic applications.
Presents a method for the analysis of time series from drifting or switching dynamics. In an extension to existing approaches that identify switches or drifts between stationary dynamical modes, the method allows one ...
详细信息
Presents a method for the analysis of time series from drifting or switching dynamics. In an extension to existing approaches that identify switches or drifts between stationary dynamical modes, the method allows one to analyze even continuously varying dynamics and can identify mixtures of more than two dynamical modes. The architecture is based on a mixture of self-organizing Nadaraya-Watson kernel estimators. The mixture model is trained by barrier optimization, a technique for constrained optimization problems. We apply the proposed method to artificially generated data and EEG recordings from the wake/sleep transition.
Handling the procedure interface in an HPF compiler is complex due to the many possible combinations of Fortran 90/HPF properties of an actual array argument and its associated dummy argument. This paper describes an ...
详细信息
This paper presents a modeling approach based on deterministic and stochastic Petri nets (DSPN) for analyzing the performance of node architectures for MIMD multiprocessor systems with distributed memory. DSPN are a n...
详细信息
This paper presents a modeling approach based on deterministic and stochastic Petri nets (DSPN) for analyzing the performance of node architectures for MIMD multiprocessor systems with distributed memory. DSPN are a numerically solvable modeling formalism with a graphical representation. The modeling approach supports design decisions for node architectures by providing quantitative results concerning processor and memory utilization for several design alternatives. To illustrate the proposed approach, DSPN of two node architectures are presented and employed for a comparative performance study.
Recent investigations have shown that vehicular traffic is the main source for emissions leading to summer smog. A study of the impact of traffic emission on urban air quality requires a complex air-pollution simulati...
详细信息
Recent investigations have shown that vehicular traffic is the main source for emissions leading to summer smog. A study of the impact of traffic emission on urban air quality requires a complex air-pollution simulation system. This paper presents results of the development and application of an air-pollution simulation system at gmdfirst which aims at supporting users in government administration and industry with forecasting and operative decision-making as well as short- to long-term regional planning. The components of the simulation system are parallelly implemented simulation models for meteorology, transport and air chemistry, data bases for model input and simulation results, as well as a graphic user interface for spatial data visualization. In order to study the influence of traffic emissions, a traffic-flow and a traffic-emission model have been added to the simulation system. Results presented are from two recent applications in the regions of Berlin/Brandenburg and Munich (Germany). Further applications are in preparation.
Data-parallel applications are usually programmed in the SPMD paradigm by using a message passing system such as MPI or PVM. However programming by using message passing primitives is still tedious and error-prone. Th...
详细信息
ISBN:
(纸本)0818678763
Data-parallel applications are usually programmed in the SPMD paradigm by using a message passing system such as MPI or PVM. However programming by using message passing primitives is still tedious and error-prone. This paper presents an abstraction of message passing programming in C++ to relieve programmers of low-level considerations. The runtime overhead introduced by the abstraction is shown to be negligible.
We present an approach to the intelligible communication of formal proofs. Observing a close correspondence between the activities of formal-proof development and program development, and using this as a guideline, we...
详细信息
This paper describes the analysis tool DSPNexpress which has been developed at the Technische Universitat Berlin since 1991. The development of DSPNexpress has been motivated by the lack of a powerful software package...
详细信息
This paper describes the analysis tool DSPNexpress which has been developed at the Technische Universitat Berlin since 1991. The development of DSPNexpress has been motivated by the lack of a powerful software package for the numerical solution of deterministic and stochastic Petri nets (DSPNs) and the complexity requirements imposed by evaluating memory consistency models for multicomputer systems. The development of DSPNexpress has gained by the author's experience with the version 1.4 of the software package GreatSPN. However, opposed to GreatSPN, the softwarearchitecture of DSPNexpress is particularly tailored to the numerical evaluation of DSPNs. Furthermore, DSPNexpress contains a graphical interface running under the X11 window system. To the best of the author's knowledge, DSPNexpress is the firstsoftware package which contains an efficient numerical algorithm for computing steady-state solutions of DSPns.
暂无评论