13 research outputs found
Evaluation of Ultra-Wideband Sensing Technology for Position Location in Indoor Construction Environments
No full textEffective construction management involves real-time decisions regarding the progress of specific activities, the location of materials and equipment, and the construction site safety. The decision making process can be improved using real-time positioning technologies such as Radio Frequency Identification Device (RFID) systems, Global Positioning System (GPS), and Ultra Wide Band (UWB) sensors. While the GPS is not applicable to indoor positioning and RFID tags cannot provide a fully automated system for position location, the characteristics of UWB systems make this technology a strong candidate for a fully automated positioning system in an indoor construction environment. This thesis presents a comprehensive study of the performance of UWB systems in a controlled laboratory environment and in an institutional construction site in Waterloo, Canada as well as for a particular safety application. A primary objective of the research was to establish the accuracy of real-time position location under various conditions, including the effect of different construction materials (e.g., wood and metal), and to analyze changes in the accuracy of position location as construction progresses and the indoor environment physically evolves. Different challenges faced in implementing such a system in an active construction environment are addressed. Based on a statistical analysis of laboratory data, and considering the construction site experience, the reliability of the UWB positioning system for the aforementioned environments is discussed. Furthermore, an automated safety system is proposed using the real-time UWB positioning technology. Based on the error modeling of the UWB position location, an optimum alarming algorithm is designed for the proposed safety system and the reliability of such system is evaluated through a statistical analysis
Automated laser scanning planning using building information modelling
No full textThe current practice in the industry for planning for scanning (P4S) is mainly manual and relies heavily on the surveyor’s judgement to choose scanning locations and
acquisition parameters. The complexity and continuous changes in construction
sites make this task challenging even for experienced surveyors. It is difficult to
ensure that the acquisition campaign fully covers scanning targets while satisfying
quality requirements.
The common approach for Planning for Scanning (P4S) involves formulating the
problem as an optimisation challenge to determine the minimum number of view
points needed to achieve complete coverage of scanning targets while meeting data
quality requirements. By using computational optimisation, scanning operations
can be streamlined to minimise on-site disruptions and data quantity without
compromising the completeness and quality of the data.
Prior P4S techniques have typically relied on a 2D plan view of the scanning
environment as input. However, 2D models lack spatial information that can
impact the quality of P4S output. With the growing availability of 3D Building
Information Modelling (BIM) models, there is a chance to enhance the P4S process
by leveraging the 3D data available.
This thesis introduces an automated P4S algorithm to bridge the knowledge gap,
which takes a 3D BIM model as input and incorporates accuracy, detail, and completeness level requirements. The algorithm also considers scanning overlap and
occlusions. Therefore, the proposed algorithm offers a reliable solution to automate
the P4S problem, resulting in more precise scanning plans that are more likely to
yield point clouds that meet the pre-defined LOA, LOD, and LOC specifications.
Real case studies were used to validate the proposed algorithm by comparing the
outcomes with those achieved by professionals. The findings illustrate the efficacy
of the algorithm, as well as its drawback in terms of computational time. The
research outcome is valuable to both technology-oriented audiences (academics,
researchers, and surveyors) and surveying-oriented audiences (scanning and surveying companies).
The proposed approach guarantees a P4S strategy that achieves the maximum
surface coverage for the target objects while fulfilling the LOA and LOD criteria,
all while suggesting the least number of scanning locations required
Planning for terrestrial laser scanning in construction: A review
No full textTerrestrial Laser Scanning (TLS) is an efficient and reliable method for collecting point clouds which have a range of applications in the Architecture, Engineering and Construction (AEC) domain. To ensure that the acquired point clouds are suitable to any given application, data collection must guarantee that all scanning targets are acquired with the specified data quality, and within time limits. Efficiency of data collection is important to reduce jobsite activity disruptions. Effective and efficient laser scanning data collection can be achieved through a prior planning optimisation process, which can be called Planning for Scanning (P4S). In the construction domain, the P4S problem has attracted increasing interest from the research community and a number of approaches have been proposed.This manuscript presents a systematic review of prior P4S works in the AEC domain and presents a categorisation of point cloud data quality criteria. The review starts with the identification and grouping in three categories of the point cloud data quality criteria that are commonly considered as constraints to the P4S problem. The three categories of data quality criteria include 1) completeness, 2) accuracy and spatial resolution, and 3) ‘registrability’. The prior P4S works are then reviewed in a structured way by contrasting them in the way they formulate the P4S optimisation problem: the type of inputs they assume (model and possible scanning locations), the constraints they consider, and the algorithm they utilise to solve the optimisation problem. This work makes two contributions: (1) it identifies gaps in knowledge that require further research such as the need to establish a fully automated scan plan which provides the optimum coverage in construction domain specifically for indoor construction; and (2) it provides a framework — principally a set of criteria — for others to compare new P4S methods against the existing state of the art in the field. This will not only be valuable for young researchers who want to start research in solving the P4S problem, but also for the ones already working in the domain to rethink the problem from different perspectives
Wayfaring in the Biomedical Sector: A Call for Re-Introducing the Toolmaker
No full textThis thesis aims to provide an understanding of the Why? and How? of a modern toolmaker, specifically within the biomedical sector, on a theoret- ical and practical level and what their role is within a product development process. Over the four years of this PhD work, a total of ten projects were completed by - or with the involvement of - the author. Framed by the grounded theory, these project provide the fundamental data for the conclusions of this thesis. In addition, a total of thirteen scientific contri- butions were - and will be - published that cover the three cornerstones of the toolmaker: The role of users, the importance of prototyping and how to successfully do it, and how this is used in the biomedical sector.
The structure of this thesis is closely following the three essential stages of product development process as encountered when using the Wayfaring method: Orienting, Probing, and Bringing it Home. In addition to high- lighting key-insights from the projects to emphasize the importance of each stage, the thesis is following the development path of the main project, a novel flow-chamber setup for cell research that was developed by the author. This project allows to reflect on a complete product development process from paper prototype to patent-pending beta-version, with a focus on why the toolmaker made all the difference.
The conclusions of this thesis are, given the nature of the scientific method, of qualitative nature and address the initially stated questions of Why? the toolmaker had an impact in the projects and How? one can implement an according role within a product development team
Wayfaring in the Biomedical Sector: A Call for Re-Introducing the Toolmaker
No full textThis thesis aims to provide an understanding of the Why? and How? of a modern toolmaker, specifically within the biomedical sector, on a theoret- ical and practical level and what their role is within a product development process. Over the four years of this PhD work, a total of ten projects were completed by - or with the involvement of - the author. Framed by the grounded theory, these project provide the fundamental data for the conclusions of this thesis. In addition, a total of thirteen scientific contri- butions were - and will be - published that cover the three cornerstones of the toolmaker: The role of users, the importance of prototyping and how to successfully do it, and how this is used in the biomedical sector.
The structure of this thesis is closely following the three essential stages of product development process as encountered when using the Wayfaring method: Orienting, Probing, and Bringing it Home. In addition to high- lighting key-insights from the projects to emphasize the importance of each stage, the thesis is following the development path of the main project, a novel flow-chamber setup for cell research that was developed by the author. This project allows to reflect on a complete product development process from paper prototype to patent-pending beta-version, with a focus on why the toolmaker made all the difference.
The conclusions of this thesis are, given the nature of the scientific method, of qualitative nature and address the initially stated questions of Why? the toolmaker had an impact in the projects and How? one can implement an according role within a product development team.digital fulltext not avialabl
18F-FDG PET/MRI and 18F-FDG PET/CT for the Management of Gynecological Malignancies: A Comprehensive Review of the Literature
No full textObjective: Positron emission tomography with 2-deoxy-2-[fluorine-18] fluoro- D-glucose integrated with computed tomography (18F-FDG PET/CT) or magnetic resonance imaging (18F-FDG PET/MRI) has emerged as a promising tool for managing various types of cancer. This review study was conducted to investigate the role of 18F- FDG PET/CT and FDG PET/MRI in the management of gynecological malignancies. Search strategy: We searched for relevant articles in the three databases PubMed/MEDLINE, Scopus, and Web of Science. Selection criteria: All studies reporting data on the FDG PET/CT and FDG PET MRI in the management of gynecological cancer, performed anywhere in the world and published exclusively in the English language, were included in the present study. Data collection and analysis: We used the EndNote software (EndNote X8.1, Thomson Reuters) to list the studies and screen them on the basis of the inclusion criteria. Data, including first author, publication year, sample size, clinical application, imaging type, and main result, were extracted and tabulated in Excel. The sensitivity, specificity, and diagnostic accuracy of the modalities were extracted and summarized. Main results: After screening 988 records, 166 studies published between 2004 and 2022 were included, covering various methodologies. Studies were divided into the following five categories: the role of FDG PET/CT and FDG-PET/MRI in the management of: (a) endometrial cancer (n = 30); (b) ovarian cancer (n = 60); (c) cervical cancer (n = 50); (d) vulvar and vagina cancers (n = 12); and (e) gynecological cancers (n = 14). Conclusions: FDG PET/CT and FDG PET/MRI have demonstrated potential as non-invasive imaging tools for enhancing the management of gynecological malignancies. Nevertheless, certain associated challenges warrant attention
Rheological properties of super critical CO2 with CuO: Multi-scale computational modeling
No full textA multi-scale computational methodology based on the density functional theory and molecular dynamics has been used to investigate the rheological properties of super critical CO2 with CuO nano-particle (NP). Density functional theory which treats the electron density as the central variable has been used to explore the adsorption of CO2 molecules on the two most stable CuO surfaces [i.e., (111) and (011)] at absolute zero. The results of this theory would provide valuable information to make CuO NPs with the surface where the CO2 adsorption is maximum in order to have a stronger mono-layer of adsorbed CO2 molecules on the surface of the NP which is the most crucial factor in formation of a stable nanofluid. The results show that the CO2 molecule is adsorbed more strongly on the (011) surface with an adsorption energy of −99.06 kJ/mol compared to the (111) surface. A computational methodology based on molecular dynamics has been used to evaluate the enhancement of the rheological properties of the super-critical CO2 liquid based nanofluid at different temperatures and pressures. In this scale, first, the CO2 liquid has been modeled by employing the condensed-phase optimized molecular potentials for atomistic simulation studies (COMPASS) force field potential and the fluid properties computed are in excellent agreement with the literature and experiment values. Second, the nanofluid has been modeled in order to study the enhancement of the fluid properties with the CuO NPs. The charged optimized many-body force field potential has been employed to consider the effect of the charge transferring between the NPs and liquid molecules and breaking of existing bonds and the formation of new bonds. The COMPASS force field potential is also employed for the interactions between CO2 molecules. The combination of these potentials is quite a new approach for the study of the super-critical (SC)-CO2 based nanofluid. The results show that the viscosity of the SC-CO2 is enhanced between 1.3 and 2.5 times under the temperature and pressure conditions studied.publishedVersion© 2018 Author(s). Locked until 11.12.2019 due to copyright restrictions
A COVID-19 pregnant patient with thrombotic thrombocytopenic purpura: a case report
No full textBackground: Pregnancy seems to increase the risk of thrombotic thrombocytopenic purpura (TTP) relapses and make the TTP more severe in any of the pregnancy trimesters, or even during the postpartum period. Case presentation: This study highlights details of treating a COVID-19 pregnant patient who survived. This 21-year addicted White woman was admitted at her 29th week and delivered a stillbirth. She was transferred to another hospital after showing signs of TTP, which was caused by a viral infection. Conclusion: This viral infection caused fever and dyspnea, and the patient was tested positive for COVID-19 infection. A chest computed tomography scan showed diffuse multiple bilateral consolidations and interlobar septal thickening. She stayed at the Intensive Care Unit for 20 days and treated with plasmapheresis. As far as we know, this is the first report of a TTP pregnant patient with COVID-19 infection. © 2021, The Author(s)
Hydrogen enhanced cracking studies on Fe-3wt%Si single and bi-crystal microcantilevers
No full text© 2017 The Author(s) Published by the Royal Society. All rights reserved. Hydrogen (H) enhanced cracking was studied in Fe-3wt%Si by means of in situ electrochemical microcantilever bending test. It was clearly shown that the presence of H causes hydrogen embrittlement (HE) by triggering crack initiation and propagation at the notch where stress concentration is existing. Additionally, the effect of carbon content and the presence of a grain boundary (GB) in the cantilever were studied. It was shown that in the presence of H the effect of carbon atom on pinning the dislocations is reduced. On the other hand, the presence of a GB, while the chemical composition of material kept constant, will promote the HE. Crack initiation and propagation occur in the presence of H, while the notch blunting was observed for both single and bicrystalline beams bent in air. Post-mortem analysis of the crack propagation path showed that a transition from transgranular fracture to intragranular fracture mechanism is highly dependent on the position of the stress concentration relative to the GB
Design and testing of a full-scale 2 MW tidal turbine blade
No full textThe Large Structures Research Group of MaREI, Orbital Marine Power Ltd and ÉireComposites Teo. have designed a full-scale blade for a next-generation 2 MW tidal turbine as part of the H2020 FloTEC project. The 8.5 m long blade will be tested under static load conditions through the H2020 MaRINET2 transnational access programme and fatigue conditions through the OCEAN ERA-NET SEABLADE project. This paper provides an overview of the initial design study which analysed the impact of using a single shear web or two shear webs in the design. The result of this design study led to optimisation of the laminates throughout the blade to reduce the cost of manufacture and, hence, the levelized cost of energy of the device. The finite element analyses were performed using the MaREI@NUI Galway composite blade design software BladeComp. From the results of the analyses a single web design was chosen for the blade. The present work also describes the set-up for the structural tests and an overview of the data acquisition and instrumentation requirements for full-scale static and fatigue blade testing.This material is in part based upon works supported by the Science Foundation Ireland Marine and Renewable Energy Ireland (MaREI) research centre under Grant No. 12/RC/2302. It was also funded by the H2020 FloTEC project and by the Ocean Energy ERA-NET Cofund grant no. 731200. The last author would like to acknowledge the support of Science Foundation Ireland through the Career Development Award programme (Grant No. 13/CDA/2200). Additional thanks are given to the technical staff at NUI Galway and engineering staff at Orbital Marine Power Ltd and ÉireComposites Teo
