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An analytical solution is undertaken to describe the wave-induced flow field and the surge motion of a permeable platform structure with fuzzy controllers in an oceanic environment. In the design procedure of the controller, a parallel distributed compensation (PDC) scheme is utilized to construct a global fuzzy logic controller by blending all local state feedback controllers. A stability analysis is carried out for a real structure system by using Lyapunov method. The corresponding boundary value problems are then incorporated into scattering and radiation problems. They are analytically solved, based on separation of variables, to obtain series solutions in terms of the harmonic incident wave motion and surge motion. The dependence of the wave-induced flow field and its resonant frequency on wave characteristics and structure properties including platform width, thickness and mass has been thus drawn with a parametric approach. From which mathematical models are applied for the wave-induced displacement of the surge motion. A nonlinearly inverted pendulum system is employed to demonstrate that the controller tuned by swarm intelligence method can not only stabilize the nonlinear system, but has the robustness against external disturbance. [ABSTRACT FROM AUTHOR]

Large-area, high-resolution visual monitoring systems are indispensable in surveillance applications. To construct such systems, high-quality image capture and display devices are required. Whereas high-quality displays have rapidly developed, as exemplified by the announcement of the 85-inch 4K ultrahigh-definition TV by Samsung at the 2013 Consumer Electronics Show (CES), high-resolution surveillance cameras have progressed slowly and remain not widely used compared with displays. In this study, we designed an innovative framework, using a dual-camera system comprising a wide-angle fixed camera and a high-resolution pan-tilt-zoom (PTZ) camera to construct a large-area, multilayered, and high-resolution visual monitoring system that features multiresolution monitoring of moving objects. First, we developed a novel calibration approach to estimate the relationship between the two cameras and calibrate the PTZ camera. The PTZ camera was calibrated based on the consistent property of distinct pan-tilt angle at various zooming factors, accelerating the calibration process without affecting accuracy; this calibration process has not been reported previously. After calibrating the dual-camera system, we used the PTZ camera and synthesized a large-area and high-resolution background image. When foreground targets were detected in the images captured by the wide-angle camera, the PTZ camera was controlled to continuously track the user-selected target. Last, we integrated preconstructed high-resolution background and low-resolution foreground images captured using the wide-angle camera and the high-resolution foreground image captured using the PTZ camera to generate a large-area, multilayered, and high-resolution view of the scene. [ABSTRACT FROM AUTHOR]

Nowadays, the Radio Frequency Identification (RFID) system enables the control of many devices over an open communication infrastructure ranging from a small home area network to the global Internet. Moreover, a variety of consumer products are tagged with remotely low-cost readable identification electromagnetic tags to replace Bar Codes. Applications such as automatic object tracking, inventory and supply chain management, and Web appliances were adopted for years in many companies. The arbitration algorithm for RFID system is used to arbitrate all the tags to avoid the collision problem with the existence of multiple tags in the interrogation field of a transponder. A splitting algorithm which is called Binary Search Tree (BST) is well known for multitags arbitration. In the current study, a splitting-based schema called Merged Search Tree is proposed to capture identification codes correctly for anticollision. Performance of the proposed algorithm is compared with the original BST according to time and power consumed during the arbitration process. The results show that the proposed model can reduce searching time and power consumed to achieve a better performance arbitration. [ABSTRACT FROM AUTHOR]

Purpose - This study aims to investigate the relationship between structural damage and sensitivity indices using the Hilbert-Huang transform (HHT) method. Design/methodology/approach - The relationship between structural damage and the sensitivity indices is obtained by using the HHT method. Three sensitivity indices are proposed: the ratio of rotation (RR), the ratio of shifting value (SV) and the ratio of bandwidth (RB). The nonlinear single degree of freedom and multiple degree of freedom models with various predominant frequencies are constructed using the SAP2000 program. Adjusted PGA El Centro and Chi-Chi (TCU068) earthquake data are used as the excitations. Next, the sensitivity indices obtained using the HHT and the fast Fourier transform (FFT) methods are evaluated separately based on the acceleration responses of the roof structures to earthquakes. Findings - Simulation results indicate that, when RR?<?1, the structural response is in the elastic region, and neither the RB nor SV in the HHT and FFT spectra change. When the structural response is nonlinear, i.e. RR1, a positive trend of change occurs in RB and RR, while in the HHT spectra, SV increases with an increasing RR. Moreover, the FFT spectra reveal that SV changes only when the RR is sufficiently large. No steady relationship between the RB and the RR can be found. Originality/value - The paper demonstrates the effectiveness of the HHT method. [ABSTRACT FROM AUTHOR]

In this study we present a fuzzy robust control design which combines H control performance with Tagagi-Sugeno (T-S) fuzzy control for the control of delayed nonlinear structural systems under external excitations. We design a nonlinear fuzzy controller based on parallel distributed compensation schemes. The controller design problem is reformulated as a linear matrix inequality (LMI) problem as derived from the Lyapunov theory. This robust method is designed to overcome the modeling error that can occur between delayed nonlinear structural systems with T-S fuzzy models. Given the fuzzy-model-based H control and the stability conditions, the stability of a delayed nonlinear structural system under external excitation is ensured. Furthermore, the delayed nonlinear structural system is equipped with a tuned mass damper designed according to the first mode of frequency. The feedback gain of the fuzzy controller is found via the Matlab LMI toolbox. The proposed method is then applied to a delayed nonlinearly tuned mass damper system. The simulation results show that not only is the proposed method able to stabilize delayed nonlinear structural systems, but also has strong robustness in terms of preventing modeling errors and external excitations. [ABSTRACT FROM AUTHOR]

In this paper, a Takagi-Sugeno (T-S) fuzzy model approach combined with a parallel distributed compensation (PDC) scheme is proposed for time-delay control of the response of a tension leg platform (TLP) system subjected to an external wave force. A global PDC-based fuzzy logic controller is constructed by blending all local state feedback controllers. A fuzzy-model-based control is thereby developed which can attenuate the influence of the external wave force. The controller is evaluated in terms of stability analysis, and the linear matrix inequality (LMI) conditions guaranteeing the stability of the TLP system derived via Lyapunov theory. A simulation example is given to show the feasibility of the proposed fuzzy control approach. The example shows the concept of half-circle fuzzy number can be used in fuzzy control and the proposed control method can be employed in practical engineering problems of oceanic structure. [ABSTRACT FROM AUTHOR]

The article focuses on understanding of landscape dynamics in arid and semi-arid environments in China. It informs that land degradation has become an important issue for land management in Western China especially the oasis ecosystem. It informs that data is collected from satellite remote sensing of terrestrial ecosystems to analyze the temporal dynamics and spatial distributions of green cover over the large area of landscape.

The fuzzy Lyapunov method is investigated for use with a class of interconnected fuzzy systems. The interconnected fuzzy systems consist of J interconnected fuzzy subsystems, and the stability analysis is based on Lyapunov functions. Based on traditional Lyapunov stability theory, we further propose a fuzzy Lyapunov method for the stability analysis of interconnected fuzzy systems. The fuzzy Lyapunov function is defined in fuzzy blending quadratic Lyapunov functions. Some stability conditions are derived through the use of fuzzy Lyapunov functions to ensure that the interconnected fuzzy systems are asymptotically stable. Common solutions can be obtained by solving a set of linear matrix inequalities (LMIs) that are numerically feasible. Finally, simulations are performed in order to verify the effectiveness of the proposed stability conditions in this paper. [ABSTRACT FROM AUTHOR]

An analytical solution is derived to describe the wave-induced flow field and surge motion of a deformable platform structure controlled with fuzzy controllers in an oceanic environment. In the controller design procedure, a parallel distributed compensation (PDC) scheme is utilized to construct a global fuzzy logic controller by blending all local state feedback controllers. The Lyapunov method is used to carry out stability analysis of a real system structure. The corresponding boundary value problems are then incorporated into scattering and radiation problems. These are analytically solved, based on the separation of variables, to obtain a series of solutions showing the harmonic incident wave motion and surge motion. The dependence of the wave-induced flow field and its resonant frequency on wave characteristics and structural properties including platform width, thickness and mass can thus be drawn with a parametric approach. The wave-induced displacement of the surge motion is determined from these mathematical models. The vibration of the floating structure and mechanical motion caused by the wave force are also discussed analytically based on fuzzy logic theory and the mathematical framework to find the decay in amplitude of the surge motion in the tension leg platform (TLP) system. The expected effects of the damping in amplitude of the surge motion due to the control force on the structural response are obvious. [ABSTRACT FROM AUTHOR]

The article presents a study on the multi-temporal variation in vegetated and non-vegetated areas in Mongolia and China to assess the desertification in East Asia. The study used variations in normalized difference vegetation index (NDVI) and the spatial data from satellite images to evaluate the vegetation dynamics. Results showed that one of the desert areas in East Asia was Southern Mongolia while the areas most at risk for desertification were Southeastern and Eastern Inner Mongolia.

Construction firms that work on a contractual basis are generally more concerned with short-term rather than long-term financial strategies. The main focus in short-term financial strategies is on working capital management (WCM). Cash management is a major factor for achieving good liquidity and profitability. In this study we take into consideration the cash component of working capital management based on the target cash balance. We develop a practical model that should allow Taiwan construction firms to utilize the currently available cash and assets at any point in time in the most rational way. To help understand the issues involved, we first introduce a model developed by Miller and Orr. The relationship between project duration and progress towards completion is most effectively represented in practical construction management by the S-curve. Thus, in this study we plot the fuzzy S-curve regression based on the Takagi-Sugeno (T-S) fuzzy model. The practicality of the model is demonstrated using project cash flow and progress payment records from a sample project. The data are obtained from the Taipei City Government's Department of Rapid Transit Systems. Some tentative conclusions concerning the model are also given. [ABSTRACT FROM AUTHOR]

This study examines the feasibility of applying adaptive fuzzy sliding mode control (AFSMC) strategies to reduce the dynamic responses of bridges constructed using a lead rubber bearing (LRB) isolation hybrid protective system. Recently developed control devices for civil engineering structures, including hybrid systems and semi-active systems, have been found to have inherent nonlinear properties. It is thus necessary to develop non-linear control methods to deal with such properties. Generally, controller fuzziness increases the robustness of the control system to counter uncertain system parameters and input excitation, and the non-linearity of the control rule increases the effectiveness of the controller relative to linear controllers. Adaptive fuzzy sliding mode control (AFSMC) is a combination of sliding mode control (SMC) and fuzzy control. The performance and robustness of these proposed control methods are all verified by numerical simulation. The results demonstrate the viability of the presented methods. The attractive control strategy derived there-from is applied to seismically excited bridges using LRB isolation. [ABSTRACT FROM AUTHOR]

Evolution of the internal solitary waves (ISWs) in the northern South China Sea (SCS) has recently attracted the attention of many oceanographers in Taiwan and the United States. These ISWs are believed to have been induced by a branch of the Kuroshio current over Luzon Strait, which propagates westward over two ridges in the Luzon Strait between Taiwan and the Philippines, and further onto the continental margin with a shelf-slope in the SCS. This paper presents some preliminary results for the evolution of a depression ISW across two triangular obstacles using numerical modelling and laboratory experiments. The experimental results confirm that the intervals and relative height between the two obstacles are important factors in the interaction of an ISW with the obstacles. However, in the case of the movement of an ISW of depression-type across the Luzon Strait, the effect of the two ridges on the characteristics of the ISW might be less significant than that from the shelf-slope, due to the variations in relative water depth. Results from numerical experiments also show that the amplitude of an ISW can be augmented once the wave commences its contact with a shelf-slope, where an internal hydraulic jump and wave breaking with vortex motion are evident in the laboratory experiments. Eventually, an ISW of depression-type could become an elevation-type at the edge of the continental shelf landwards beyond the turning point, where the upper layer is larger than the bottom layer in a stratified water column. [ABSTRACT FROM AUTHOR]

Purpose - This study aims to apply a systematic statistical approach, including several plot indexes, to diagnose the goodness of fit of a logistic regression model, and then to detect the outliers and influential observations of the data from experimental data. Design/methodology/approach - The proposed statistical approach is applied to analyze some experimental data on internal solitary wave propagation. Findings - A suitable logistic regression model in which the relationship between the response variable and the explanatory variables is found. The problem of multicollinearity is tested. It was found that certain observations would not have the problem of multicollinearity. The P-values for both the Pearson and deviance ?2 tests are greater than 0.05. However, the Pearson ?2 value is larger than the degrees of freedom. This finding indicates that although this model fits the data, it has a slight overdispersion. After three outliers and influential observations (cases 11, 27, and 49) are removed from the data, and the remaining observations are refitted the goodness-of-fit of the revised model to the data is improved. Practical implications - A comparison of the four predictive powers: R2, max-rescaled R2, the Somers' D, and the concordance index c, shows that the revised model has better predictive abilities than the original model. Originality/value - The goodness-of-fit and prediction ability of the revised logistic regression model are more appropriate than those of the original model. [ABSTRACT FROM AUTHOR]

Purpose - Fuzzy theory provides a rigorous, flexible approach to the problem of defining and computing. Therefore, to facilitate decision making in a geographic information system (GIS), the graph layer indicator and the Takagi-Sugeno (T-S) fuzzy model must be integrated. This study aims to explain several versions of the T-S fuzzy model based on fuzzy theory and fuzzy operation. Design/methodology/approach - An inference model is constructed for GIS using the T-S fuzzy model to formulate an integrated T-S decision-making (TSDMK) system. Findings - The TSDMK system accommodates inexact, linguistic, vague and uncertain GIS data. The operator assigns most graph layer indicators by intuition. Practical implications - Simulation results for the Hualien main station show that the proposed TSDMK system is an effective approach for GIS decision making. Originality/value - This investigation assesses applications of fuzzy logic for decision making in a GIS based on TSDMK graphs focusing on model-based systems. [ABSTRACT FROM AUTHOR]

This article proposes a design method for producing H∞ control performance for structural systems using the Tagagi-Sugeno (T-S) fuzzy model. A structural system with a tuned mass damper is modeled using a T-S type fuzzy model. Using the parallel distributed compensation (PDC) scheme, we design a nonlinear fuzzy controller for the tuned mass damper system. A sufficient stability condition for the control system is derived in terms of Lyapunov theory and this control problem is reformulated into solving the linear matrix inequalities (LMI) problem, Finally. the tuned mass damper is designed based on the first modal frequency of the control system and a fuzzy controller to stabilize the structural system is then found using the Matlab LMI toolbox. A simulation example is given to show the feasibility of the prolapsed fuzzy controller design method. [ABSTRACT FROM AUTHOR]

Purpose - This study seeks to develop a systematic means of identifying regression models using a complex regression model with a statistical method. Design/methodology/approach - As a widely adopted statistical scheme for analyzing multifactor data, regression analysis provides a conceptually simple algorithm for examining functional relationships among variables. This investigation assesses the proposed relationship using a sample of data in regression analysis and then estimates the fit using statistics. Furthermore, several algorithms and added variable plots are presented to obtain an appropriate regression model and the relationship between response variables y, p and explanatory variables x0,x1,x2,???,xp. Findings - The proposed statistical scheme is demonstrated by the analysis of experimental data on internal waves, in which the results can well illustrate what has been investigated in laboratory experiment and may be applicable to the naturally occurring reflection of internal waves from sloping bottoms. Practical implications - In previous studies, field observations of internal waves were carried out. Owing to the limit of stationary measurement in situ, sufficient experiment data were not easily obtained. On the other hand, data collected by laboratory experiments express more information on wave mechanism, such as energy dissipation, mixing efficiency, and stratification thickness in a stratified layer fluid system. In present study, the authors supply valuable experiment data and analytic method, which will be a great contribution to the geophysical fluid dynamics. The results illustrate well what has been investigated in laboratory experiment and may be applicable to the naturally occurring reflection of internal waves from sloping bottoms. Originality/value - More recently, it has been proposed that internal wave mixing may contribute significantly to internal mixing in the ocean and hence has an important influence on world climatic changes. Based on the statistical algorithm and regression model, the reduction in internal wave energy can be predicted on a sloping bottom due to frictional effect. Since, interaction between internal waves and uniform slopes has occurred in an estuary, a lake or in the ocean, the results available in this paper would benefit future study on internal wave hydrodynamics. [ABSTRACT FROM AUTHOR]

The stabilization problem is considered in this study for a nonlinear system. It is shown that the stability analysis of nonlinear systems can be reduced into linear matrix inequality (LMI) problems. First, the neural-network (NN) model is employed to approximate a nonlinear system via the backpropagation algorithm. Then, a linear differential inclusion (LDI) state-space representation is established for the dynamics of the NN model. In terms of Lyapunov's direct method, a sufficient condition is provided to guarantee the stability of nonlinear systems. Based on this criterion, a model-based fuzzy controller is then designed to stabilize the nonlinear system and the H 8 control performance is achieved at the same time. Finally, two examples with numerical simulations are given to illustrate the control methodology. [ABSTRACT FROM AUTHOR]

A robustness design of fuzzy control via model-based approach is proposed in this paper to overcome the effect of approximation error between nonlinear system and Takagi-Sugeno (T-S) fuzzy model. T-S fuzz model is used to model the resonant and chaotic systems and the parallel distributed compensation (PDC) is employed to determine structures of fuzzy controllers. Linear matrix inequality (LMI) based design problems are utilized to find common definite matrices P and feedback gains K satisfying stability conditions derived in terms of Lyapunov direct method. Finally, the effectiveness and the feasibility of the proposed controller design method is demonstrated through numerical simulations on the chaotic and resonant systems. [ABSTRACT FROM AUTHOR]

To overcome the effect of modeling errors between nonlinear multiple time-delay subsystems and Takagi­Sugeno (T-S) fuzzy models with multiple time delays, a robustness design of fuzzy control is proposed in this paper. In terms of Lyapunov's direct method, a delay-dependent stability criterion is hence derived to guarantee the asymptotic stability of nonlinear multiple time-delay large-scale systems. Based on this criterion and the decentralized control scheme, a set of model-based fuzzy controllers is then synthesized via the technique of parallel distributed compensation (PDC) to stabilize the nonlinear multiple time-delay large-scale system. Finally, a numerical example with simulations is given to demonstrate the concepts discussed throughout this paper. [ABSTRACT FROM AUTHOR]

Discusses the application of fuzzy H∞ control via Takagi-Sugeno (T-S) fuzzy models for nonlinear time-delay systems. Determination of the structures of fuzzy controllers from the T-S fuzzy models; Demonstration of the proposed controller design method through numerical simulations on the chaotic and resonant systems.