A spatially dense wireless sensor network was designed, developed and installed on a long-span suspension bridge for a 3-month deployment to record ambient acceleration. A total 174 sets of data 1.3 GB were collected from 64 sensor nodes on the main span and south tower of the Golden Gate Bridge. Analysis of the vibration data using power spectral densities and peak picking provide approximate ...

The author reviewed in this paper current microneurographic findings on the responses of muscle sympathetic nerve activity (MSNA) and skin sympathetic nerve activity (SSNA) to the environment in humans with special reference to vibration-induced white finger (VWF). 1) MSNA was enhanced by +Gz gravitational input, while being suppressed by simulated weightlessness through the baroreflex mechanis...

Many vibration suppression systems are required to function across a variety of different temperatures, yet most literature ignores the effects of temperature changes on the structure and on the closed loop response. This paper presents an experimental implementation of a vibration suppression system based on a piezoceramic actuator that effectively controls vibration of a clamped panel as it u...

Ambient energy harvesting has been in recent years the recurring object of a number of research efforts aimed at providing an autonomous solution to the powering of small-scale electronic mobile devices. Among the different solutions, vibration energy harvesting has played a major role due to the almost universal presence of mechanical vibrations. Here we propose a new method based on the explo...

The issues surrounding the use of ambient vibration modes for the location of structural damage via dynamically measured flexibility are examined. Several methods for mass-normalizing the dynamic mode shapes extracted from ambient modal data are implemented and compared. The methods are applied to data from a series of ambient modal tests on an actual highway bridge. The results indicate that t...

The paper summarizes the results of recent ambient vibration tests and operational modal analyses carried out on the new curved cable-stayed bridge erected in the Commercial Harbour of Porto Marghera (Venice, Italy). The ambient vibration tests were carried out as a part of the reception tests of the bridge before its opening and included the recordings of the system response in selected points...

This note details the effect of telescope static and dynamic wavefront errors on the performance of future AO systems at Keck observatory. Measurements at Keck are used to bound probable values of the input errors. Current understanding of all errors appears sufficient to design the NGAO system. A notable exception is the full aperture tip tilt vibrations at 29 Hz. These errors appear to have s...

This paper investigates dynamic characteristics of a historic wooden structure by ambient vibration testing, presenting a novel estimation methodology of story stiffness for the purpose of vibration-based structural health monitoring. As for the ambient vibration testing, measured structural responses are analyzed by two output-only system identification methods (i.e., frequency domain decompos...