NDT techniques such as impact-echo and impact acoustic available for the integrity assessment of concrete bridge can be employed to locate void, cracks, honeycombing, and delamination in concrete decks and slabs, as w...
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ISBN:
(纸本)0415403154
NDT techniques such as impact-echo and impact acoustic available for the integrity assessment of concrete bridge can be employed to locate void, cracks, honeycombing, and delamination in concrete decks and slabs, as well as other concrete structure. These two methods have the similar theoretical background, i.e., both of them are performed by introducing a stress pulse impact source (such as a ball drop or hammer strike) at the surface of a structure and monitoring the stress waves with a transducer (impact-echo method) or microphone (impact acoustic method). Stress waves propagate into the structure and are reflected by the external surface and existing voids or delaminations, and thus to create a resonance condition which can be observed by a spectrum analysis of the acquired waveforms. The resonance frequency provides critical information about the structure geometry, soundness of the structure, and the acoustic behavior of interfaces between materials (Sansalone et al 1989;Sansalone et al 1997). One advantage of these two methods is that access to only one surface of a structure is needed, making them suitable for rapid assessment of structure. The processing of the stress waves is generally implemented in the frequency domain. As a method for evaluation of the relative integrity degree of concrete structures, the relative change in the frequency content of the measured signal compared with the signal from the sound parts of the structure indicates the presence of a fault (such as void and interfacial delamination), variation of structure geometry, or a modification in concrete characteristics, or all three. Other than frequency domain property, some other soundness indices (such as amplitude ratio between input and output, averaged center frequency) are developed and implemented via statistical analysis to extract valuable information for evaluation (Haya et al 2003;watanabe et al 2004). Practically, there are numerous factors (such as interface condition, mate
E-health is closely related with networks and telecommunications when dealing with applications of collecting or transferring medical data from distant locations for performing remote medical collaborations and diagno...
ISBN:
(数字)9781598290370
E-health is closely related with networks and telecommunications when dealing with applications of collecting or transferring medical data from distant locations for performing remote medical collaborations and diagnosis. In this book we provide an overview of the fields of image and signal processing for networked and distributed e-health applications and their supporting technologies. The book is structured in 10 chapters, starting the discussion from the lower end, that of acquisition and processing of biosignals and medical images and ending in complex virtual reality systems and techniques providing more intuitive interaction in a networked medical environment. The book also discusses networked clinical decision support systems and corresponding medical standards, WWW-based applications, medical collaborative platforms, wireless networking, and the concepts of ambient intelligence and pervasive computing in electronic healthcare systems.
We have developed scanning laser range sensor called "SOKUIKI" sensor which is ultra-small scanning laser range sensor adopted for various types of mobile robots as we have already published. As a sensor for...
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The role of mobile phones in contemporary life is a means to access to the wireless internet service not to mention a device for general communication. Even if additional functions and services are provided for use, t...
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The adaptive observer for the nonlinear time-varying continuous-time system has been proposed in this paper. Also, a novel state-space adaptive observer-based tracker scheme for nonlinear time-varying sampled-data sys...
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ISBN:
(纸本)0889865515
The adaptive observer for the nonlinear time-varying continuous-time system has been proposed in this paper. Also, a novel state-space adaptive observer-based tracker scheme for nonlinear time-varying sampled-data systems, which have unanticipated decay factors in the actuators, has been proposed in this paper. Here, we utilize the advantage of digital redesign methodology to convert a theoretically well-designed analog controller/observer with a high-gain property into its corresponding low-gain digital controller/observer for a practical implementation.
Energy efficiency of cache memories is crucial in designing embedded processors. Reducing energy consumption in the instruction cache is especially important, since the instruction cache consumes a significant portion...
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This paper presents a new topological localization system for mobile robot navigation based on salient visual regions. These salient regions are obtained by computing the opponencies of color and texture among multi-s...
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We propose an image file compression method using Region Growing and Interpolation. Firstly, using the techniques of Region Growing, we divide the image in blocks. The compression-decompression method is based on biva...
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An approach for restoring the images of a suspected person taken by a security camera with dirty lens is proposed In the approach, the peculiar facts concerning the security camera system that all the things in the im...
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Using equivalent circuit analysis, the dynamic behavior of ultrasonic wave propagation in solid metals is investigated in this study, particularly in Langevin vibrators clamped with a resonant amplifier to enlarge the...
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