A Parametric Study of a Drive by Bridge Inspection System Based on the Morlet Wavelet

Many of the bridges currently in use worldwide are approaching the end of their design lives. However, rehabilitating and extending the lives of these structures raises important safety issues. There is also a need for increased monitoring which has considerable cost implications for bridge management systems. Existing structural health monitoring (SHM) techniques include vibration-based approaches which typically involve direct instrumentation of the bridge and are important as they can indicate the deterioration of the bridge condition. However, they can be labour intensive and expensive. In the past decade, alternative indirect vibration-based approaches which utilise the response of a vehicle passing over a bridge have been developed. This paper investigates such an approach; a low-cost approach for the monitoring of bridge structures which consists of the use of a vehicle fitted with accelerometers on its axles. The approach aims to detect damage in the bridge while obviating the need for direct instrumentation of the bridge. Here, the effectiveness of the approach in detecting damage in a bridge is investigated using a simplified vehicle-bridge interaction (VBI) model in theoretical simulations and a scaled VBI model in a laboratory experiment. In order to identify the existence and location of damage, the vehicle accelerations are recorded and processed using a continuous Morlet wavelet transform and a damage index is established. A parametric study is carried out to investigate the effect of parameters such as the bridge span length, vehicle speed, vehicle mass, damage level and road surface roughness on the accuracy of results.

A wavelet based drive-by bridge inspection system

This paper investigates a low-cost wavelet-based approach for the preliminary monitoring of bridge structures, consisting of the use of a vehicle fitted with accelerometers on its axles. The approach aims to reduce the need for direct instrumentation of the bridge. A time-frequency analysis is carried out in order to identify the existence and location of damage from vehicle accelerations. Firstly, in theoretical simulations, a simplified vehicle-bridge interaction model is used to investigate the effectiveness of the approach. A number of damage indicators are evaluated and compared. A range of parameters such as the bridge span, vehicle speed, damage level and location, signal noise and road roughness are varied in simulations. Secondly, a scaled laboratory experiment is carried out to validate the results of the theoretical analysis and assess the ability of the selected damage indicators to detect changes in the bridge response from vehicle accelerations. 

What a girl's gotta do: the labor of the biopolitical celebrity in austerity Britain

This article debunks the widespread view that young female celebrities, especially those who rise to fame through reality shows and other forms of media-orchestrated self-exposure, dodge “real” work out of laziness, fatalism, and a misguided sense of entitlement. Instead, the authors argue that becoming a celebrity in a neoliberal economy such as that of the United Kingdom, where austerity measures disproportionately disadvantage the young, women, and the poor, is not as irregular or exceptional a choice as previously thought, especially since the precariousness of celebrity earning power adheres to the current demands of the neoliberal economy on its workforce. What is more, becoming a celebrity involves different forms of labor that are best described as biopolitical, since such labor fully involves and consumes the human body and its capacities as a living organism. Weight gain and weight loss, pregnancy, physical transformation through plastic surgery, physical symptoms of emotional distress, and even illness and death are all photographically documented and supplemented by extended textual commentary, usually with direct input from the celebrity, reinforcing and expanding on the visual content. As well as casting celebrity work as labor, the authors also maintain that the workings of celebrity should always be examined in the context of wider cultural, social and real economies.

Anderson County's labor potential: with a projection for the future

This report by the State Development Board and the Anderson Chamber of Commerce is a survey of present labor availability and future labor supply in Anderson County. Statistics include employment status, school enrollment including college, projection of school dropouts, and projection of new entries in work force with and without high school education.

Liberalization of Labor Relations in Germany and the United States: A firm-centered comparison of cross-national labor organizing at Amazon and Volkswagen

Thesis (Master's)--University of Washington, 2015

Estratégias e internacionalização na manutenção e produção

Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia Mecânica

Vision-Based Assisted Teleoperation for Inspection Tasks with a Small ROV

It is well-known that ROVs require human intervention to guarantee the success of their assignment, as well as the equipment safety. However, as its teleoperation is quite complex to perform, there is a need for assisted teleoperation. This study aims to take on this challenge by developing vision-based assisted teleoperation maneuvers, since a standard camera is present in any ROV. The proposed approach is a visual servoing solution, that allows the user to select between several standard image processing methods and is applied to a 3-DOF ROV. The most interesting characteristic of the presented system is the exclusive use of the camera data to improve the teleoperation of an underactuated ROV. It is demonstrated through the comparison and evaluation of standard implementations of different vision methods and the execution of simple maneuvers to acquire experimental results, that the teleoperation of a small ROV can be drastically improved without the need to install additional sensors.

Structured Light System for Underwater Inspection Operations

In this work we propose the development of a stereo SLS system for underwater inspection operations. We demonstrate how to perform a SLS calibration both in dry and underwater environments using two different methods. The proposed methodology is able to achieve quite accurate results, lower than 1 mm in dry environments. We also display a 3D underwater scan of a known object size, a sea scallop, where the system is able to perform a scan with a global error lower than 2% of the object size.

Effects of Local Anesthetic on the Time Between Analgesic Boluses and the Duration of Labor in Patient-Controlled Epidural Analgesia: Prospective Study of Two Ultra-Low Dose Regimens of Ropivacaine and Sufentanil

BACKGROUND: Patient-controlled epidural analgesia with low concentrations of anesthetics is effective in reducing labor pain. The aim of this study was to assess and compare two ultra-low dose regimens of ropivacaine and sufentanil (0.1% ropivacaine plus 0.5 μg.ml-1 sufentanil vs. 0.06% ropivacaine plus 0.5 μg.ml-1 sufentanil) on the intervals between boluses and the duration of labor. MATERIAL AND METHODS: In this non-randomized prospective study, conducted between January and July 2010, two groups of parturients received patient-controlled epidural analgesia: Group I (n = 58; 1 mg.ml-1 ropivacaine + 0.5 μg.ml-1 sufentanil) and Group II (n = 57; 0.6 mg.ml-1 ropivacaine + 0.5 μg.ml-1 sufentanil). Rescue doses of ropivacaine at the concentration of the assigned group without sufentanil were administered as necessary. Pain, local anesthetic requirements, neuraxial blockade characteristics, labor and neonatal outcomes, and maternal satisfaction were recorded. RESULTS: The ropivacaine dose was greater in Group I (9.5 [7.7-12.7] mg.h-1 vs. 6.1 [5.1-9.8 mg.h-1], p < 0.001). A time increase between each bolus was observed in Group I (beta = 32.61 min, 95% CI [25.39; 39.82], p < 0.001), whereas a time decrease was observed in Group II (beta = -1.40 min, 95% CI [-2.44; -0.36], p = 0.009). The duration of the second stage of labor in Group I was significantly longer than that in Group II (78 min vs. 65 min, p < 0.001). CONCLUSIONS: Parturients receiving 0.06% ropivacaine exhibited less evidence of cumulative effects and exhibited faster second stage progression than those who received 0.1% ropivacaine.

On the labor share the long-run equilibrium and its adjustment process

This research computes an Equilibrium Labor Share using a VECM for a panel of 19 countries, analyzes what determines the speed at which the labor share adjusts towards that equilibrium and decomposes this adjustment in terms of real wages and employment. Results suggest that the speed at which a country adjusts decreases with employment protection legislation and labor taxes. Most countries’ labor shares adjustment is made through real wages changes instead of changing employment, suggesting that wage moderation policies may play an important role on the adjustment process without harming employment. Keywords: Equilibrium

A wave of change: Labor market and social security impacts of the EU refugee inflow

The recent massive inflow of refugees to the European Union (EU) raises a number of unanswered questions on the economic impact of this phenomenon. To examine these questions, we constructed an overlapping-generations model that describes the evolution of the skill premium and of the welfare benefit level in relevant European countries, in the aftermath of an inflow of asylum-seekers. In our simulation, relative wages of skilled workers increase between 8% and 11% in the period of the inflow; their subsequent time path is dependent on the initial skill premium. The entry of migrants creates a fiscal surplus of about 8%, which can finance higher welfare benefits in the subsequent periods. These effects are weaker in a scenario where refugees do not fully integrate into the labor market.

On the labor share the long-run equilibrium and its adjustment process

This research computes an Equilibrium Labor Share using a VECM for a panel of 19 countries, analyzes what determines the speed at which the labor share adjusts towards that equilibrium and decomposes this adjustment in terms of real wages and employment. Results suggest that the speed at which a country adjusts decreases with employment protection legislation and labor taxes. Most countries’ labor shares adjustment is made through real wages changes instead of changing employment, suggesting that wage moderation policies may play an important role on the adjustment process without harming employment.