911 research outputs found
Data fusion strategy for precise vehicle location for intelligent self-aware maintenance systems
Abstractâ Nowadays careful measurement applications are
handed over to Wired and Wireless Sensor Network. Taking
the scenario of train location as an example, this would lead to
an increase in uncertainty about position related to sensors
with long acquisition times like Balises, RFID and
Transponders along the track. We take into account the data
without any synchronization protocols, for increase the
accuracy and reduce the uncertainty after the data fusion
algorithms. The case studies, we have analysed, derived from
the needs of the project partners: train localization, head of an
auger in the drilling sector localization and the location of
containers of radioactive material waste in a reprocessing
nuclear plant. They have the necessity to plan the maintenance
operations of their infrastructure basing through architecture
that taking input from the sensors, which are localization and
diagnosis, maps and cost, to optimize the cost effectiveness and
reduce the time of operation
Precise vehicle location as a fundamental parameter for intelligent selfaware rail-track maintenance systems
The rail industry in the UK is undergoing substantial changes in response to a modernisation vision for 2040. Development and implementation of these will lead to a highly automated and safe railway. Real-time regulation of traffic will optimise the performance of the network, with trains running in succession within an adjacent movable safety zone. Critically, maintenance will use intelligent trainborne and track-based systems. These will provide accurate and timely information for condition based intervention at precise track locations, reducing possession downtime and minimising the presence of workers in operating railways. Clearly, precise knowledge of trainsâ real-time location is of paramount importance.
The positional accuracy demand of the future railway is less than 2m. A critical consideration of this requirement is the capability to resolve train occupancy in adjacent tracks, with the highest degree of confidence. A finer resolution is required for locating faults such as damage or missing parts, precisely.
Location of trains currently relies on track signalling technology. However, these systems mostly provide an indication of the presence of trains within discrete track sections. The standard Global Navigation Satellite Systems (GNSS), cannot precisely and reliably resolve location as required either.
Within the context of the needs of the future railway, state of the art location technologies and systems were reviewed and critiqued. It was found that no current technology is able to resolve location as required. Uncertainty is a significant factor. A new integrated approach employing complimentary technologies and more efficient data fusion process, can potentially offer a more accurate and robust solution. Data fusion architectures enabling intelligent self-aware rail-track maintenance systems are proposed
Osteoporosis after Stroke: A Review of the Causes and Potential Treatments
Osteoporosis is a known consequence of stroke, associated with an increased incidence of fractures, mainly of the hip, leading to further disability. The pattern of bone loss seen in stroke patients is different from that usually encountered with postmenopausal osteoporosis, since it is limited to the paretic side and more evident in the upper extremities. Several factors appear to have an influence on bone mass in stroke patients, such as the degree of paresis, gait disability and the duration of immobilization. The pathogenesis of osteoporosis after stroke remains unclear. Paresis, reduced mobility and reduced bone load seem to play a major role. Other factors such as nutritional and iatrogenic ones may also play an important part. In this paper, the clinical evidence, pathophysiology and possible treatments of poststroke osteoporosis will be reviewed
The Digital Twin Realization of an Ejector for Multiphase Flows
Despite the extensive use of ejectors in the process industry, it is complex to predict suction and motive fluids mixture characteristics, especially with multiphase flows, even if, in most cases, mixture pressure control is necessary to satisfy process requirements or to avoid performance problems. The realization of an ejector model can allow the operators to overcome these difficulties to have real-time control of the system performance. In this context, this work proposes a framework for developing a Digital Twin of an ejector installed in an experimental plant able to predict the future state of an item and the impact of negative scenarios and faults diagnosis. ANNs have been identified as the most used tool for simulating the multiphase flow ejector. Nevertheless, the complexity in defining their structure and the computational effort to train and use them are not suitable for realizing standalone applications onboard the ejector. The proposed paper shows how Swarm Intelligence algorithms require a low computational complexity and overperform prediction error and computational effort. Specifically, the Grey Wolf optimizer proves to be the best one among those analyzed
Relation of project managers' personality and project performance: an approach based on value stream mapping
Purpose: This work investigates the influence of project managersâ personality on the success of a project in a Multinational Corporation. The methodology proposed for analyzing the project managersâ personality is based on the Myers-Briggs Type Indicator.
Design/methodology/approach: Forty projects carried out in 2012 by multinational corporation, concerning new product development (NPD), have been analyzed, comparing the profile of project managers with results obtained in terms of traditional performance indexes (time delay and over-budget of projects) and performance indexes usually used in âLean Productionâ sector (waste time and type of âwastesâ). A detailed analysis of the most important âwastesâ during the project development is carried out using the Value Stream Mapping (VSM) technique.
Findings and Originality/value: Relying on the MyersâBriggs personality instrument, results show that extroverted managers (as opposed to introverted managers) carry out projects that show lower delay and lower waste time. Introverted managers often make âOver-processingâ and âDefectâ types of waste. Moreover, lower delay and over-budget have been shown by perceiving managers.
Research limitations: Regarding the limitations of this work it is necessary to highlight that we collected data from project managers in a retrospective way. While we believe that several aspects of our data collection effort helped enhance the accuracy of the results, future research could conduct real-time case study research to get more detailed insights into the proposed relationships and avoid retrospective bias. Moreover we focused on a single respondent, the project manager. This helped us ensure that their interpretations played an important role in product development. But, we cannot examined the opinion of team members that could be different from project managers opinion regarding some questions.
Originality/value: This research provides insight useful to develop proactive approaches to prevent project failures, including the creation of more effective messages and methods to help companies to make the best choices during managersÂŽ hiring. Moreover this research would allow organizations to better match the short-term organizational needs with appropriate personality types.Peer Reviewe
A design method for improving assembly and environmental sustainability in packaging solutions: a case study in household appliances
By using a functional requirement analysis, through Design for Manufacture and Assembly and Design for Environment principles, this paper aims at showing a new design method to improve the overall assembly features and environmental sustainability of a packaging solution. This method provides to rank functional requirements according to three different design specifications and also to the number of relationships they have with each other. At the same time, a ranked order of importance for the packaging parts has been realised, considering the number of performed functions. The purpose of this method is to support the designers in focusing their attention on the most important packaging parts and, at the same time, giving them a clear idea of which are the most important functional requirements to be satisfied. This study has been focused on domestic household packaging, but the provided method can be extended to any particular packaging solution and its findings are still valid. According to the Design for Environmental perspective, the actual and the new resulting packaging solutions have been then compared through Life Cycle Assessment method. The results have shown the new packaging solution being able to cut down the environmental impacts, on average, of approximately 30%
sustainability analysis of friction stir welding of aa5754 sheets
Abstract The environmental impact of friction stir welding process vs. welding parameters was evaluated and analysed in detail. To this purpose, butt joints in AA5754 aluminum alloy sheets were obtained at different rotational and welding speeds. All input and output data, in terms of materials, energies and emissions, were collected and analyzed using a life cycle assessment software in order to evaluate the environmental impact index. Sound weld was used as functional unit and all energy and material flows were based on it. The results given by the life cycle assessment analysis has shown that the environmental impact of friction stir welding is strongly affected by rotational and welding speeds. The environmental impact was also related to the mechanical properties of joints, expressed as ultimate tensile strength and ultimate elongation
autonomic cardiovascular control in hyperthyroid women during sleep
Hyperthyroidism is characterized by hyperadrenergic symptoms (i.e., tachycardia, anxiety, and increased metabolic state). Although hyperthyroid patients often complain about an impairment of sleep, no data are available on sleep characteristics and autonomic cardiovascular control during sleep in these patients. We aimed to assess sleep qualitative indices and autonomic cardiovascular regulation during sleep in hyperthyroidism (Hyperthyr) and after treatment. Six subjects with a first diagnosis of Graves' disease or hyperfunctioning nodule underwent a complete polysomnographic study (PSG) at the time of diagnosis and after the treatment, when they became euthyroid (Euthyr). ECG and respiratory signals were extracted and samples of consecutive 250â300 beats were analyzed using linear spectral and nonlinear entropy analysis of heart rate variability (HRV), during the different sleep stages. Heart rate was decreased and total power increased in Euthyr compared to Hyperthyr, both during wake and sleep; no changes of the sympathovagal balance were observed. Entropy analysis showed that regularity index was reduced in Euthyr compared to Hyperthyr, suggesting changes in the complexity of the cardiovascular control. Periodic leg movements (PLM) were reduced in Euthyr compared to Hyperthyr. In conclusion, hyperthyroidism seems to be associated with an increased sleep fragmentation, due to PLM and an altered cardiac autonomic control
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