Using Instrumented Vehicles To Detect Damage in Bridges

Bridge structures are subject to continuous degradation due to the environment, ageing and excess loading. Monitoring of bridges is a key part of any maintenance strategy as it can give early warning if a bridge is becoming unsafe. This paper will theoretically assess the ability of a vehicle fitted with accelerometers on its axles to detect changes in damping of bridges, which may be the result of damage. Two vehicle models are used in this investigation. The first is a two degree-of-freedom quarter-car and the second is a four degree-of-freedom halfcar. The bridge is modelled as a simply supported beam and the interaction between the vehicle and the bridge is a coupled dynamic interaction algorithm. Both smooth and rough road profiles are used in the simulation and results indicate that changes in bridge damping can be detected by the vehicle models for a range of vehicle velocities and bridge spans.

Using Instrumented Vehicles to Detect Damage in Bridges

This paper describes a ‘drive-by’ method of bridge inspection using an instrumented vehicle. Accelerometers on the vehicle are proposed as a means of detecting damage on the bridge in the time it takes for the vehicle to cross the bridge at full highway speed. For a perfectly smooth road profile, the method is shown to be feasible. Changes in bridge damping, which is an indicator of damage, are clearly visible in the acceleration signal of a quarter-car vehicle on a smooth road surface modelled using MatLab. When road profile is considered, the influence of changes in bridge damping on the vehicle acceleration signal is much less clear. However, when a half-car model is used on a road with a rough profile, it is again possible to detect changes in bridge damping, provided the vehicle has two identical axles.

PTF11iqb: cool supergiant mass-loss that bridges the gap between Type IIn and normal supernovae

PTF11iqb was initially classified as a TypeIIn event caught very early after explosion. It showed narrow Wolf-Rayet (WR) spectral features on day 2, but the narrow emission weakened quickly and the spectrum morphed to resemble those of Types II-L and II-P. At late times, Halpha emission exhibited a complex, multipeaked profile reminiscent of SN1998S. In terms of spectroscopic evolution, we find that PTF11iqb was a near twin of SN~1998S, although with weaker interaction with circumstellar material (CSM) at early times, and stronger CSM interaction at late times. We interpret the spectral changes as caused by early interaction with asymmetric CSM that is quickly (by day 20) enveloped by the expanding SN ejecta photosphere, but then revealed again after the end of the plateau when the photosphere recedes. The light curve can be matched with a simple model for weak CSM interaction added to the light curve of a normal SN~II-P. This plateau requires that the progenitor had an extended H envelope like a red supergiant, consistent with the slow progenitor wind speed indicated by narrow emission. The cool supergiant progenitor is significant because PTF11iqb showed WR features in its early spectrum --- meaning that the presence of such WR features in an early SN spectrum does not necessarily indicate a WR-like progenitor. [abridged] Overall, PTF11iqb bridges SNe~IIn with weaker pre-SN mass loss seen in SNe II-L and II-P, implying a continuum between these types.

FlexiArch-stress ribbon combination for multi-span pedestrian bridges

The potential benefits of combining the elegance of the stress ribbon concept with the robustness and speed of construction of the FlexiArch is discussed. In combination, multi-span pedestrian/cycle bridges which are innovative, highly durable and have optimal full life cycle costs can be produced with lengths of over 100 m. As the stress ribbon system is well known, the main emphasis of this paper will be on the FlexiArch. Since 1900 few arch bridges have been built, but with the development of the innovative FlexiArch this trend can be reversed as they can be installed rapidly, are cost competitive, have all the attributes of masonry arches and are very sustainable. Thus the FlexiArch represents a very attractive alternative to heavily reinforced cast in situ arches currently used in combination with stress ribbon deck systems.

The battle of Cable Street

This witness seminar on the events in the East End of London of 4 October 1936, traditionally known as the ‘Battle of Cable Street’, was held at the Institute of Historical Research on 1 May 1991. It was chaired by Professor Geoffrey Alderman and introduced by Noreen Branson. The participants were Sid Bailey (former member of the BUF), Dr David Cesarani, Tony Gilbert, Charlie Goodman, Joyce Goodman, Professor Colin Holmes, Frank Lesser, Kevin Morgan (biographer of Harry Pollitt), Phil Piratin (Communist MP for Mile End 1945–50), Michael Quill, Jack Shaw, Harold Smith, Ronald F. Webb (former member of the BUF) and Len Wise (former member of the BUF). Yvonne Kapp was unable to attend but she sent a short account of her recollections of the event and this has been included with this transcript.

Clinician-Perceived Bridges and Barriers to Parental Implementation of Picture Exchange Communication System (PECS): An evaluation.

Picture Exchange Communication System (PECS) is an augmentative and alternative communicative system that improves communication and decreases problem behaviors in children with Developmental Disabilities and Autism. The mediator model is a validated approach that clinicians use to train parents to perform evidence-based interventions. Parental non-adherence to treatment recommendations is a documented problem. This qualitative study investigated clinician-perceived factors that influence parental adherence to PECS recommendations. Three focus groups (n=8) were conducted with Speech Language Pathologists and Behavior Therapists experienced in providing parents with PECS recommendations. Constant comparison analysis was used. In general, clinicians believed that PECS was complex to implement. Thirty-one bridges were identified to overcome complexity. Twenty-two barriers and 6 other factors also impacted parental adherence. Strategies to address these factors were proposed based on a review of the literature. Future research will be performed to validate these findings using parents and a larger sample size.

Chart of bill of timber in bridges, culverts, cattle-guard and roadways, signed by S.D. Woodruff

Chart of bill of timber in bridges, culverts, cattle-guard and roadways, signed by S.D. Woodruff, Oct. 18, 1855.

Cable to L.C.O. Woodruff from Mona Foster

Cable to L.C.O. Woodruff from Mona Foster. She asks if she should sell the securities and invest in war loans, n.d.

Proyecto técnico - económico para implementar un sistema de televisión por cable (CATV) en la ciudad de Trujillo-Perú

Tesis (Maestría en Ciencias de la Administración en Especialidaden Finanzas) UANL

La televisión por cable en México : su administración y planeación financiera

Tesis (Maestría en Administración de Empresas) UANL

Proyecto técnico - económico para implementar un sistema de televisión por cable (CATV) en la ciudad de Trujillo-Perú

Tesis (Maestría en Ciencias de la Administración en Especialidad en Finanzas) - UANL, 1997

Diseño de un sistema de televisión por cable en la Facultad de Ingeniería Mécanica y Eléctrica

Tesis (Maestro en Ciencias de la Ingeniería Eléctrica con Especialidad en Eléctronica) - Universidad Autónoma de Nuevo León, 2000

The latin american network of women transforming the economy : building bridges between economic justice and gender equity

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

Policy gradient based Reinforcement Learning for real autonomous underwater cable tracking

This paper proposes a field application of a high-level reinforcement learning (RL) control system for solving the action selection problem of an autonomous robot in cable tracking task. The learning system is characterized by using a direct policy search method for learning the internal state/action mapping. Policy only algorithms may suffer from long convergence times when dealing with real robotics. In order to speed up the process, the learning phase has been carried out in a simulated environment and, in a second step, the policy has been transferred and tested successfully on a real robot. Future steps plan to continue the learning process on-line while on the real robot while performing the mentioned task. We demonstrate its feasibility with real experiments on the underwater robot ICTINEU AUV