98,486 research outputs found

    A survey on gain-scheduled control and filtering for parameter-varying systems

    Get PDF
    Copyright © 2014 Guoliang Wei et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.This paper presents an overview of the recent developments in the gain-scheduled control and filtering problems for the parameter-varying systems. First of all, we recall several important algorithms suitable for gain-scheduling method including gain-scheduled proportional-integral derivative (PID) control, H 2, H ∞ and mixed H 2 / H ∞ gain-scheduling methods as well as fuzzy gain-scheduling techniques. Secondly, various important parameter-varying system models are reviewed, for which gain-scheduled control and filtering issues are usually dealt with. In particular, in view of the randomly occurring phenomena with time-varying probability distributions, some results of our recent work based on the probability-dependent gain-scheduling methods are reviewed. Furthermore, some latest progress in this area is discussed. Finally, conclusions are drawn and several potential future research directions are outlined.The National Natural Science Foundation of China under Grants 61074016, 61374039, 61304010, and 61329301; the Natural Science Foundation of Jiangsu Province of China under Grant BK20130766; the Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning; the Program for New Century Excellent Talents in University under Grant NCET-11-1051, the Leverhulme Trust of the U.K., the Alexander von Humboldt Foundation of Germany

    Neural synchrony in cortical networks : history, concept and current status

    Get PDF
    Following the discovery of context-dependent synchronization of oscillatory neuronal responses in the visual system, the role of neural synchrony in cortical networks has been expanded to provide a general mechanism for the coordination of distributed neural activity patterns. In the current paper, we present an update of the status of this hypothesis through summarizing recent results from our laboratory that suggest important new insights regarding the mechanisms, function and relevance of this phenomenon. In the first part, we present recent results derived from animal experiments and mathematical simulations that provide novel explanations and mechanisms for zero and nero-zero phase lag synchronization. In the second part, we shall discuss the role of neural synchrony for expectancy during perceptual organization and its role in conscious experience. This will be followed by evidence that indicates that in addition to supporting conscious cognition, neural synchrony is abnormal in major brain disorders, such as schizophrenia and autism spectrum disorders. We conclude this paper with suggestions for further research as well as with critical issues that need to be addressed in future studies

    Neural synchrony in cortical networks : history, concept and current status

    Get PDF
    Following the discovery of context-dependent synchronization of oscillatory neuronal responses in the visual system, the role of neural synchrony in cortical networks has been expanded to provide a general mechanism for the coordination of distributed neural activity patterns. In the current paper, we present an update of the status of this hypothesis through summarizing recent results from our laboratory that suggest important new insights regarding the mechanisms, function and relevance of this phenomenon. In the first part, we present recent results derived from animal experiments and mathematical simulations that provide novel explanations and mechanisms for zero and nero-zero phase lag synchronization. In the second part, we shall discuss the role of neural synchrony for expectancy during perceptual organization and its role in conscious experience. This will be followed by evidence that indicates that in addition to supporting conscious cognition, neural synchrony is abnormal in major brain disorders, such as schizophrenia and autism spectrum disorders. We conclude this paper with suggestions for further research as well as with critical issues that need to be addressed in future studies

    Costs and benefits of inter-departmental innovation collaboration

    Get PDF
    Inter-departmental innovation collaboration facilitates innovation performance. At the same time, it has been identified as source of increased coordination costs. Using organizational information processing theory, this paper builds and tests hypotheses on the costs and benefits of innovation-related collaboration within firms. Based on a sample of 433 German manufacturing firms we show inter-departmental innovation collaboration to increase process innovation performance, but also to produce costs in terms of project delay and project termination. These costs, however, do not affect innovation performance at the firm level. This finding suggests firms to be well able to balance the costs and benefits of interdepartmental collaboration across their innovation project portfolio. Theoretical and managerial implications are discussed. --Inter-departmental innovation collaboration,innovation performance,project delay,project termination

    Estimating integrated water vapor trends from VLBI, GPS,and numerical weather models: sensitivity totropospheric parameterization

    Get PDF
    ©2018. American Geophysical UnionIn this study, we estimate integrated water vapor (IWV) trends from very long baseline interferometry (VLBI) and global navigation satellite systems (GNSS) data analysis, as well as from numerical weather models (NWMs). We study the impact of modeling and parameterization of the tropospheric delay from VLBI on IWV trends. We address the impact of the meteorological data source utilized to model the hydrostatic delay and the thermal deformation of antennas, as well as the mapping functions employed to project zenith delays to arbitrary directions. To do so, we derive a new mapping function, called Potsdam mapping functions based on NWM data and a new empirical model, GFZ‐PT. GFZ‐PT differs from previous realizations as it describes diurnal and subdiurnal in addition to long‐wavelength variations, it provides harmonic functions of ray tracing‐derived gradients, and it features robustly estimated rates. We find that alternating the mapping functions in VLBI data analysis yields no statistically significant differences in the IWV rates, whereas alternating the meteorological data source distorts the trends significantly. Moreover, we explore methods to extract IWV given a NWM. The rigorously estimated IWV rates from the different VLBI setups, GNSS, and ERA‐Interim are intercompared, and a good agreement is found. We find a quite good agreement comparing ERA‐Interim to VLBI and GNSS, separately, at the level of 75%.DFG, 255986470, GGOS-SIM-2: Simulation des "Global Geodetic Observing System

    Regional integration in South Asia : what role for trade facilitation ?

    Get PDF
    The trade performance of countries in South Asia over the past two decades has been poor relative to other regions. Exports from South Asia have doubled over the past 20 years to approximately USD 100 billion. In contrast, East Asia's exports grew ten times over the same period. The low level of intraregional trade has contributed to weak export performance in South Asia. The empirical analysis in this paper demonstrates gains to trade in the region from reform and capacity building in trade facilitation at the regional level. When considering intraregional trade, if countries in South Asia raise capacity halfway to East Asia's average, trade is estimated to rise by USD 2.6 billion. This is approximately 60 percent of the total intraregional trade in South Asia. Countries in the region also have a stake in the success of efforts to promote capacity building outside its borders. If South Asia and the rest of the world were to raise their levels of trade facilitation halfway to the East Asian average, the gains to the region would be estimated at USD 36 billion. Out of those gains, about 87 percent of the total would be generated from South Asia's own efforts (leaving the rest of the world unchanged). In summary, we find that the South Asian region's expansion of trade can be substantially advanced with programs of concrete action to address barriers to trade facilitation to advance regional goals.Transport Economics Policy&Planning,Transport and Trade Logistics,Common Carriers Industry,Trade Policy,Free Trade

    Testing in the incremental design and development of complex products

    Get PDF
    Testing is an important aspect of design and development which consumes significant time and resource in many companies. However, it has received less research attention than many other activities in product development, and especially, very few publications report empirical studies of engineering testing. Such studies are needed to establish the importance of testing and inform the development of pragmatic support methods. This paper combines insights from literature study with findings from three empirical studies of testing. The case studies concern incrementally developed complex products in the automotive domain. A description of testing practice as observed in these studies is provided, confirming that testing activities are used for multiple purposes depending on the context, and are intertwined with design from start to finish of the development process, not done after it as many models depict. Descriptive process models are developed to indicate some of the key insights, and opportunities for further research are suggested
    corecore