71,403 research outputs found

    Trajectory tracking in 2D under fuzzy controller with variable sampling

    Get PDF
    AbstractThe paper deals with an effective approach of the robust controller design based on the fuzzy logic, and algorithms for variable sampling of trajectory points to improve the control performance of trajectory tracking. The proposed controller design and sampling algorithms are verified in the case study of the selected mechatronic system. All presented results are reached in co-simulation of two different modeling environments, Matlab-Simulink and MSC Adams. MSC Adams is used for the dynamics of the mechatronic system and Matlab-Simulink for the control part of the co-simulation, respectively

    Gryphon Injection Wing Modeling

    Get PDF
    Imperial Users onl

    Liquids-Rich Shale Evaluation: Modelling and Optimization of Hydraulically Fractured Liquids-Rich Shale Wells

    Get PDF
    Imperial Users onl

    Performance of Geant4 in simulating semiconductor particle detector response in the energy range below 1 MeV

    Full text link
    Geant4 simulations play a crucial role in the analysis and interpretation of experiments providing low energy precision tests of the Standard Model. This paper focuses on the accuracy of the description of the electron processes in the energy range between 100 and 1000 keV. The effect of the different simulation parameters and multiple scattering models on the backscattering coefficients is investigated. Simulations of the response of HPGe and passivated implanted planar Si detectors to \beta{} particles are compared to experimental results. An overall good agreement is found between Geant4 simulations and experimental data

    Subband filtered multi-carrier systems for multi-service wireless communications

    Get PDF
    Flexibly supporting multiple services, each with different communication requirements and frame structure, has been identified as one of the most significant and promising characteristics of next generation and beyond wireless communication systems. However, integrating multiple frame structures with different subcarrier spacing in one radio carrier may result in significant inter-service-band-interference (ISBI). In this paper, a framework for multi-service (MS) systems is established based on a subband filtered multi-carrier system. The subband filtering implementations and both asynchronous and generalized synchronous (GS) MS subband filtered multi-carrier (SFMC) systems have been proposed. Based on the GS-MS-SFMC system, the system model with ISBI is derived and a number of properties on ISBI are given. In addition, low-complexity ISBI cancelation algorithms are proposed by precoding the information symbols at the transmitter. For asynchronous MS-SFMC system in the presence of transceiver imperfections, including carrier frequency offset, timing offset, and phase noise, a complete analytical system model is established in terms of desired signal, inter-symbol-interference, inter-carrier-interference, ISBI, and noise. Thereafter, new channel equalization algorithms are proposed by considering the errors and imperfections. Numerical analysis shows that the analytical results match the simulation results, and the proposed ISBI cancelation and equalization algorithms can significantly improve the system performance in comparison with the existing algorithms

    Index to 1984 NASA Tech Briefs, volume 9, numbers 1-4

    Get PDF
    Short announcements of new technology derived from the R&D activities of NASA are presented. These briefs emphasize information considered likely to be transferrable across industrial, regional, or disciplinary lines and are issued to encourage commercial application. This index for 1984 Tech B Briefs contains abstracts and four indexes: subject, personal author, originating center, and Tech Brief Number. The following areas are covered: electronic components and circuits, electronic systems, physical sciences, materials, life sciences, mechanics, machinery, fabrication technology, and mathematics and information sciences

    QTM: computational package using MPI protocol for quantum trajectories method

    Full text link
    The Quantum Trajectories Method (QTM) is one of {the} frequently used methods for studying open quantum systems. { The main idea of this method is {the} evolution of wave functions which {describe the system (as functions of time). Then,} so-called quantum jumps are applied at {a} randomly selected point in time. {The} obtained system state is called as a trajectory. After averaging many single trajectories{,} we obtain the approximation of the behavior of {a} quantum system.} {This fact also allows} us to use parallel computation methods. In the article{,} we discuss the QTM package which is supported by the MPI technology. Using MPI allowed {utilizing} the parallel computing for calculating the trajectories and averaging them -- as the effect of these actions{,} the time {taken by} calculations is shorter. In spite of using the C++ programming language, the presented solution is easy to utilize and does not need any advanced programming techniques. At the same time{,} it offers a higher performance than other packages realizing the QTM. It is especially important in the case of harder computational tasks{,} and the use of MPI allows {improving the} performance of particular problems which can be solved in the field of open quantum systems.Comment: 28 pages, 9 figure

    An assessment of the value of simulation based learning within an aeromedical service in Johannesburg, South Africa

    Get PDF
    MSc (Nursing), Faculty of health Sciences, University of the WitwatersrandThis quasi-experimental study assesses the value of simulation based learning for a medical flight crew within an air ambulance service based in Johannesburg, South Africa. The purpose of this study was to assess the value of simulation based learning for air medical crew in performing synchronized cardioversion efficiently, effectively and safely within the air medical environment. The objectives were to determine if there is a difference between the experimental group that had been exposed to a simulation-based learning experience versus a control group that had not, in respect of performing synchronized cardioversion and scene management pertaining to this skill. This was a qausi-experimental study in which stratified random sampling was done to divide the participants into the control and experimental groups using medical qualification as homogenous subsets. The outcome of the study showed that the control group was quicker to first shock than the participants in the experimental group. However, the participants in the experimental group performed the skill more effectively, with regard to doing / following the correct steps in performing the skill of synchronized cardioversion and were safer practitioners. None of the variants within the sample groups had a significant effect on performance of the skill. The conclusion is that within this specific air ambulance service, simulation- based learning improved the performance of synchronized cardioversion in comparison to the normal orientation / training provided in the service

    SDL based validation of a node monitoring protocol

    Full text link
    Mobile ad hoc network is a wireless, self-configured, infrastructureless network of mobile nodes. The nodes are highly mobile, which makes the application running on them face network related problems like node failure, link failure, network level disconnection, scarcity of resources, buffer degradation, and intermittent disconnection etc. Node failure and Network fault are need to be monitored continuously by supervising the network status. Node monitoring protocol is crucial, so it is required to test the protocol exhaustively to verify and validate the functionality and accuracy of the designed protocol. This paper presents a validation model for Node Monitoring Protocol using Specification and Description Llanguage (SDL) using both Static Agent (SA) and Mobile Agent (MA). We have verified properties of the Node Monitoring Protocol (NMP) based on the global states with no exits, deadlock states or proper termination states using reachability graph. Message Sequence Chart (MSC) gives an intuitive understanding of the described system behavior with varying node density and complex behavior etc.Comment: 16 pages, 24 figures, International Conference of Networks, Communications, Wireless and Mobile 201
    corecore