Damage Identification for Prestressed Adjacent Box-Beam Bridges

Structural health monitoring (SHM) has gained considerable attention as a tool for monitoring the health of civil infrastructure. For bridge infrastructure, previous methods have focused on the detection of localized damage through modal parameters extracted from the longitudinal direction of the structure. This paper investigates a new damage detection method based on the change in the first vertical mode extracted from the transverse direction of the bridge. The mode is determined through application of modal curve fitting to frequency response functions (FRFs) that are formed using vertical response data obtained in the direction perpendicular to the bridge’s longitudinal axis. Using this method, both local damage and global damage in the bridge reveal themselves as having a localized effect on the bridge response. Furthermore, damage is revealed in such a way that it enables differentiation of the damage types. To demonstrate the effectiveness of the method, modal parameters were extracted from acceleration data obtained from a finite element model of a full bridge. Analysis of the modal parameters showed that the proposed approach could not only detect both local and global bridge damage, but could also differentiate between damage types using only one mode shape. The proposed method was compared to a previously developed SHM method

A Study of Labour Force Flows 1961-80. Quarterly Economic Commentary Special Article, May 1982

A Study of Labour Force Flows

Studies on Pre-slaughter Handling of Pigs and its Relationship to Meat Quality

End of Project ReportsTwo quality defects of pork which are affected by preslaughter handling are PSE (Pale Soft Exudative) and DFD (Dark Firm Dry) meat. The incidence of PSE pork is mainly a function of the breed of pig but short-term stressful handling before slaughter and feeding too close to slaughter are also involved. DFD meat is a result of prolonged stressful handling. PSE meat is pale and uneven in colour and exudes fluid making it unattractive in the retail display while dark meat appears stale and is prone to bacterial spoilage. After slaughter muscle metabolism continues and muscle glycogen is converted to lactic acid reducing meat pH. Prolonged stress results in glycogen depletion, pre-slaughter feeding results in elevated levels. Colour may be assessed subjectively by eye or objectively by a meter colour but pH of the meat is closely related to colour and measurement of pH at 45 minutes post-slaughter is frequently used to predict ultimate colour and pH. The objective of this study was to examine pre-slaughter handling practices and their relationship with meat quality (pH, colour). In the first trial, a survey of the amounts of stomach contents in pigs at slaughter in two factories found similar amounts to comparable surveys in France and the UK. It was concluded that most pigs had been fasted for an adequate time before delivery. The relationship between the amount of stomach contents and meat quality in this survey was poor. In the second trial, pigs from the Moorepark herd fed by either a computerised wet feeding system or an ad libitum dry feed system were slaughtered after overnight fasting or with feed available up to loading for transport to the factory, two to three hours before slaughter. There was no difference between feeding systems in meat colour or pH but fasted pigs, on both feeding systems, had darker meat and meat of a higher pH. In the third and fourth trials a survey of transport vehicles was carried out and meat quality of pigs delivered in modern and old-type vehicles was compared. Most trucks examined (78%) were four years old or more. Few had modern hydraulic lifting gear for the top decks. Space allowances during transportation were generally adequate but delays in unloading could, in warm weather, cause stress on pigs. There was little evidence for an effect of vehicle on meat quality parameters but day to day variation in carcass temperature and pH suggested a need for further research on factory influences on meat quality. Feeding of Magneium Aspartate to pigs for the last 5 days prior to slaughter has been shown, in Australia, to have a beneficial effect on meat colour and drip loss. In the final trial in this study Mg Asp had no effect on meat quality parameters.European Union Structural Funds (EAGGF

Multimodal sensor fusion for low-power wearable human motion tracking systems in sports applications

This paper presents a prototype human motion tracking system for wearable sports applications. It can be particularly applicable for tracking human motion during executing certain strength training exercises, such as the barbell squat, where an inappropriate technique could result in an injury. The key novelty of the proposed system is twofold. Firstly, it is an inside-out, multimodal, motion tracker that incorporates two complementary sensor modalities, i.e. a camera and an inertial motion sensor, as well as two externally-mounted points of reference. Secondly, it incorporates a novel multimodal sensor fusion algorithm which uses the complementary nature of vision and inertial sensor modalities to perform a computationally efficient 3-Dimensional (3-D) pose detection of the wearable device. The 3-D pose is determined by fusing information about the two external reference points captured by the camera together with the orientation angles captured by the inertial motion sensor. The accuracy of the prototype was experimentally validated in laboratory conditions. The main findings are as follows. The Root Mean Square Error (RMSE) in 3-D position calculation was 36.7 mm and 13.6 mm in the static and mobile cases, respectively. Whereas the static case was aimed at determining the system’s performance at all 3-D poses within the work envelope, the mobile case was used to determine the error in tracking human motion that is involved in the barbell squat, i.e. a mainly repeated vertical motion pattern

Low cost embedded multimodal opto-inertial human motion tracking system

Human motion tracking systems are widely used in various application spaces, such as motion capture, rehabilitation, or sports. There exists a number of such systems in the State-Of-The-Art (SOA) that vary in price, complexity, accuracy and the target applications. With the continued advances in system integration and miniaturization, wearable motion trackers gain in popularity in the research community. The opto-inertial trackers with multimodal sensor fusion algorithms are some of the common approaches found in SOA. However, these trackers tend to be expensive and have high computational requirements. In this work, we present a prototype version of our opto-inertial, motion tracking system that offers a low-cost alternative. The 3D position and orientation are determined by fusing optical and inertial sensor data together with knowledge about two external reference points using a purpose-designed data fusion algorithm. An experimental validation was carried out on one of the use cases that this system is intended for, i.e. barbell squat in strength training. The results showed that the total RMSE in position and orientation was 32.8 mm and 0.89 degree, respectively. It operated in real-time at 20 frames per second

Enabling effective operational decision making on a Combined Heat and Power System using the 5C architecture

The use of Cyber Physical Systems (CPS) to optimise industrial energy systems is an approach which has the potential to positively impact on manufacturing sector energy efficiency. The need to obtain data to facilitate the implementation of a CPS in an industrial energy system is however a complex task which is often implemented in a non-standardised way. The use of the 5C CPS architecture has the potential to standardise this approach. This paper describes a case study where data from a Combined Heat and Power (CHP) system located in a large manufacturing company was fused with grid electricity and gas models as well as a maintenance cost model using the 5C architecture with a view to making effective decisions on its cost efficient operation. A control change implemented based on the cognitive analysis enabled via the 5C architecture implementation has resulted in energy cost savings of over €7400 over a four-month period, with energy cost savings of over €150,000 projected once the 5C architecture is extended into the production environment

Concept for a Distributed, Modular, In-space Robotically Assembled, RF Communication Payload in GEO

In this paper, we discuss a concept for a Radio Frequency (RF) Ka band communications payload that is robotically assembled and serviced in space using a servicing vehicle such as the Robotic Servicing of Geosynchronous Satellites (RSGS) vehicle being developed by the Defense Advance Research Projects Agency (DARPA). Our work focuses on how to modularize a representative Ka band communications payload into discrete modules that are hosted on a persistent platform. In our concept, each module consists of a primary aperture and the associated RF and electronics required to serve a particular coverage area or type. These modules are notionally packaged in a form factor capable of launching as a secondary payload via an EELV Secondary Payload Adapter (ESPA) ring or a Payload Orbital Delivery System (PODS) module. The overall payload consists of an earth coverage module, regional coverage modules, high gain regional coverage modules, and a host interface unit (HIU). We discuss the notional capabilities and requirements of each module. We present two different architecture concepts corresponding to two different persistent platform concepts. In one concept, the persistent platform is made up of small, independent spacecraft that are connected together with structural members with communication channels. The payload modules are hosted on the individual spacecraft. In the second approach, the platform consists of a large central spacecraft with a structural truss that has power, communication and thermal loops. The payload modules are hosted on the truss through standard interfaces. We present aspects of the mission concept on how the payload may be modularized, launched (as secondary launch elements), acquired by the RSGS vehicle in space and assembled on to the persistent platform. We discuss the robotics aspects of assembly and servicing of the payload modules. A key aspect of this concept is the serviceability of the payload. Central to the modular and discrete payload design is an intent to refurbish the payload incrementally as technology evolves or the components fail. Existing geosynchronous communication satellites are designed and built as monolithic spacecraft which makes any servicing beyond refueling fairly complicated. This makes it hard to take advantage of the post launch evolution in technology, particularly in the electronics elements. Our concept is aimed at modularizing the payload such that the modules, particularly the electronics elements, can be easily serviced using the RSGS vehicle. Our concept attempts to take advantage of the long service life of high reliability system components in the core satellite bus while allowing rapid expansion and upgrading of the communications payload through the addition and replacement of individual payload modules

Concept for a Distributed, Modular, In-space Robotically Assembled, RF Communication Payload in GEO

In this paper, we discuss a concept for a Radio Frequency (RF) Ka band communications payload that is robotically assembled and serviced in space using a servicing vehicle such as the Robotic Servicing of Geosynchronous Satellites (RSGS) vehicle being developed by the Defense Advance Research Projects Agency (DARPA). Our work focuses on how to modularize a representative Ka band communications payload into discrete modules that are hosted on a persistent platform. In our concept, each module consists of a primary aperture and the associated RF and electronics required to serve a particular coverage area or type. These modules are notionally packaged in a form factor capable of launching as a secondary payload via an EELV Secondary Payload Adapter (ESPA) ring or a Payload Orbital Delivery System (PODS) module. The overall payload consists of an earth coverage module, regional coverage modules, high gain regional coverage modules, and a host interface unit (HIU). We discuss the notional capabilities and requirements of each module. We present two different architecture concepts corresponding to two different persistent platform concepts. In one concept, the persistent platform is made up of small, independent spacecraft that are connected together with structural members with communication channels. The payload modules are hosted on the individual spacecraft. In the second approach, the platform consists of a large central spacecraft with a structural truss that has power, communication and thermal loops. The payload modules are hosted on the truss through standard interfaces. We present aspects of the mission concept on how the payload may be modularized, launched (as secondary launch elements), acquired by the RSGS vehicle in space and assembled on to the persistent platform. We discuss the robotics aspects of assembly and servicing of the payload modules. A key aspect of this concept is the serviceability of the payload. Central to the modular and discrete payload design is an intent to refurbish the payload incrementally as technology evolves or the components fail. Existing geosynchronous communication satellites are designed and built as monolithic spacecraft which makes any servicing beyond refueling fairly complicated. This makes it hard to take advantage of the post launch evolution in technology, particularly in the electronics elements. Our concept is aimed at modularizing the payload such that the modules, particularly the electronics elements, can be easily serviced using the RSGS vehicle. Our concept attempts to take advantage of the long service life of high reliability system components in the core satellite bus while allowing rapid expansion and upgrading of the communications payload through the addition and replacement of individual payload modules

Drug-gut microbiota interactions: implications for neuropharmacology

The fate and activity of drugs are frequently dictated not only by the host per se but also by the microorganisms present in the gastrointestinal tract. The gut microbiome is known to, both directly and indirectly, affect drug metabolism. More evidence now hints at the impact that drugs can have on the function and composition of the gut microbiome. Both microbiota-mediated alterations in drug metabolism and drug-mediated alterations in the gut microbiome can have beneficial or detrimental effects on the host. Greater insights into the mechanisms driving these reciprocal drug-gut microbiota interactions are needed, to guide the development of microbiome-targeted dietary or pharmacological interventions, with the potential to enhance drug efficacy or reduce drug side-effects. In this review, we explore the relationship between drugs and the gut microbiome, with a specific focus on potential mechanisms underpinning the drug-mediated alterations on the gut microbiome and the potential implications for psychoactive drugs

Point tracking with lensless smart sensors

This paper presents the applicability of a novel Lensless Smart Sensor (LSS) developed by Rambus, Inc. in 3D positioning and tracking. The unique diffraction pattern attached to the sensor enables more precise position tracking than possible with lenses by capturing more information about the scene. In this work, the sensor characteristics is assessed and accuracy analysis is accomplished for the single point tracking scenario