We analyze an optical fiber sensor based on a concatenated fiber Bragg grating (FBG) with long period grating (LPG) with transfer matrix method and experiment. First, we optimize parameters of concatenated structure i...
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Delay-time and energy constraints have a significant impact on the design and operation of wireless sensor and actuator networks(WSANs).Aiming for a class of random sudden events,the real-time actuator scheduling stra...
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ISBN:
(纸本)9789881563842
Delay-time and energy constraints have a significant impact on the design and operation of wireless sensor and actuator networks(WSANs).Aiming for a class of random sudden events,the real-time actuator scheduling strategy is proposed based on the event driven in *** proposed scheduling strategy,three performance indexes,such as reaction time,energy consumption and energy distribution of whole network are considered at the same *** translate the actuator scheduling strategy into a multi-objective optimization ***,the optimal solution of the multi-objective issues is usually not able to be *** solve the problems,we first obtain the optimal solution of a single objective,and then make each performance index try to be close to own optimization solution via normalizing the evaluation function in order to achieve multi-objective approximate optimization *** approach is called the normalization optimization *** extended simulations illustrate the proposed actuator scheduling strategy is feasible and effective in WSANs.
Novel safety systems are needed to meet the growing demand of railway operation. In this paper we introduce general techniques for the detection of tracks and their components in 3D laser scanning data. These techniqu...
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ISBN:
(纸本)9781479961153
Novel safety systems are needed to meet the growing demand of railway operation. In this paper we introduce general techniques for the detection of tracks and their components in 3D laser scanning data. These techniques make use of feature based methods, such as support vector machines, as well as model based methods, such as template matching. The focus of this work are robust and precise detectors for infrastructure elements, such as rails, tracks, closure rails, and frogs. These parts can be used for both, track maintenance and train-borne localization. The approach is evaluated experimentally on 3D laser scanning data and compared with a reference system. Furthermore, the approach is generic such that it can be used for data of any suitable laser scanning system.
Background: Previous attempts to characterise the burden of chronic respiratory diseases have focused only on specific disease conditions, such as chronic obstructive pulmonary disease (COPD) or asthma. In this study,...
Background: Previous attempts to characterise the burden of chronic respiratory diseases have focused only on specific disease conditions, such as chronic obstructive pulmonary disease (COPD) or asthma. In this study, we aimed to characterise the burden of chronic respiratory diseases globally, providing a comprehensive and up-to-date analysis on geographical and time trends from 1990 to 2017. Methods: Using data from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017, we estimated the prevalence, morbidity, and mortality attributable to chronic respiratory diseases through an analysis of deaths, disability-adjusted life-years (DALYs), and years of life lost (YLL) by GBD super-region, from 1990 to 2017, stratified by age and sex. Specific diseases analysed included asthma, COPD, interstitial lung disease and pulmonary sarcoidosis, pneumoconiosis, and other chronic respiratory diseases. We also assessed the contribution of risk factors (smoking, second-hand smoke, ambient particulate matter and ozone pollution, household air pollution from solid fuels, and occupational risks) to chronic respiratory disease-attributable DALYs. Findings: In 2017, 544·9 million people (95% uncertainty interval [UI] 506·9–584·8) worldwide had a chronic respiratory disease, representing an increase of 39·8% compared with 1990. Chronic respiratory disease prevalence showed wide variability across GBD super-regions, with the highest prevalence among both males and females in high-income regions, and the lowest prevalence in sub-Saharan Africa and south Asia. The age-sex-specific prevalence of each chronic respiratory disease in 2017 was also highly variable geographically. Chronic respiratory diseases were the third leading cause of death in 2017 (7·0% [95% UI 6·8–7·2] of all deaths), behind cardiovascular diseases and neoplasms. Deaths due to chronic respiratory diseases numbered 3 914 196 (95% UI 3 790 578–4 044 819) in 2017, an increase of 18·0% since 1990, while
The article proposes a method that gives the ability to consider the mathematical model of the system as a symmetry-preserving one, even if the conditions of the symmetry for the plant model are not met or if the symm...
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The article proposes a method that gives the ability to consider the mathematical model of the system as a symmetry-preserving one, even if the conditions of the symmetry for the plant model are not met or if the symmetry was lost during the system operation. The proposed approach is based here on an active disturbance rejection scheme, which assumes an augmentation of the system model, which further leads to an online reconstruction and attenuation of the effects of terms in the plant, that preclude its model from being a symmetry-preserving one. The effectiveness of the proposed technique is presented in the paper using an illustrative example, supported with simulation results.
An application of the set-point controller expressed in generalized velocity components for an airship is presented in this paper. The nonlinear controller was proposed originally for fully actuated underwater vehicle...
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ISBN:
(纸本)9781479959020
An application of the set-point controller expressed in generalized velocity components for an airship is presented in this paper. The nonlinear controller was proposed originally for fully actuated underwater vehicles. However, in this work it is shown that the same controller can be used for an airship, thanks the velocity transformation, and it is able to detect risk resulting from lost or reduction gain coefficients. Consequently, the shown approach appears an useful tool for investigation of the control algorithm in case of some flight disturbances of motion. It is worth of notice that the analysis gives further insight into the airship dynamics. The performance of the applied controller is tested by simulation on a 6-DOF model of the airship.
In this paper, a global state feedback tracking controller for surface vehicles is presented. Here, the hovercraft robot model is considered. The controller is designed after transformation the vehicle equations of mo...
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ISBN:
(纸本)9781479959020
In this paper, a global state feedback tracking controller for surface vehicles is presented. Here, the hovercraft robot model is considered. The controller is designed after transformation the vehicle equations of motion. The main feature of this controller is that it can be used both for fully actuated and underactuated systems. This feature arises from the fact that the dynamics of the vehicle is taken into consideration. The stability of the designed controller is demonstrated based on a Lyapunov method. The controller can be used, in general, for various moving systems as unmanned underwater vehicle, hovercrafts or airships. In this note however, simulation results on a 3-DOF underactuated hovercraft demonstrate the effectiveness of the given approach.
The work analyses the use of an active disturbance rejection control (ADRC) structure in a constant water pressure management system. The adaptability and robustness of the proposed control scheme significantly enhanc...
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The work analyses the use of an active disturbance rejection control (ADRC) structure in a constant water pressure management system. The adaptability and robustness of the proposed control scheme significantly enhances the performance of a conventional PID-based output feedback control loop. The paper investigates the ADRC approach with a set of experiments conducted on a laboratory-scale model of a water supply system. The proposed approach is also compared with the results obtained for the sole conventional industrial PID controller.
In this paper, the conventional Fuzzy Cognitive Maps (FCMs), which has already achieved success in many fields, are extended by using triangular fuzzy numbers (TFNs). The advantage of FCMs is that they are relatively ...
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In this paper, the conventional Fuzzy Cognitive Maps (FCMs), which has already achieved success in many fields, are extended by using triangular fuzzy numbers (TFNs). The advantage of FCMs is that they are relatively easy to construct and parameterize and are capable of handling the full range of system feedback structure, including density-dependent effects. However, it is a well-known fact that there are some limitations inherent in FCM, such as lack of adequate capability to handle uncertain information and lack of enough ability to aggregate the information from different sources. Triangular fuzzy numbers which are represented by a triplet has the capacity to represent the uncertain relations between the concepts. In this context, the weight matrix representing the causal relations are enhanced to a fuzzy weight matrix that has TFNs as element. As a result of this improvement, the dynamic reasoning algorithm of the conventional FCM is improved for the use of the proposed novel FCM. The proposed FCM is presented via four simulations and the results are discussed. The results of the simulation study shows how easily the uncertain information can be represented and interpreted by the proposed FCM design methodology.
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