• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 6
  • 5
  • 2
  • 1
  • Tagged with
  • 22
  • 22
  • 16
  • 7
  • 6
  • 6
  • 5
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Analysis of Electroanatomic Mapping System Accuracy Using X-ray Reconstruction of Electrode Locations in a Porcine Animal Model

Boudlali, Hana 01 December 2020 (has links) (PDF)
Fluoroscopy is considered the gold standard for locating catheters during cardiac electrophysiology (EP) procedures. However, fluoroscopy emits ionizing radiation which can lead to adverse health effects when exposed to in high doses (World Health Organization, 2016). Electroanatomic mapping (EAM) systems display the three-dimensional location of EP catheters and measure the local electrical activity of the heart. They can minimize a physician’s reliance on fluoroscopy and can help reduce radiation exposure during a case (Casella, 2011). EAM systems are diagnostic medical devices that inform the placement of ablation therapy and must accurately locate catheters to be deemed safe. Test methods to determine EAM system accuracy should be compared back to a gold standard, such as fluoroscopy. Fluoroscopy only provides a two-dimensional image of the catheter location, which is not a suitable ground truth for measuring the three-dimensional accuracy of EAM systems. X-Ray Reconstruction of Electrode Locations (XRROEL) calculates the true three-dimensional catheter location by performing a coordinate transform on two-dimensional fluoroscopy images. This thesis outlines the development and validation of the XRROEL method in a porcine animal model, and describes how XRROEL can be applied to optimize the location accuracy of electroanatomic mapping system algorithms.
2

Demolish-IT : the development of a process management tool for the demolition industry

Qu, S. January 2010 (has links)
Today most demolition projects undertaken are complex and involve many parties who must comply with a myriad of regulations as well as other constraints (e.g. finance). The management of demolition projects requires individual team members to have a wide range of skills and knowledge in addition to practical experience. Demolition processes currently operated are frequently performed in an unstructured, intuitive manner with considerable reliance on experience, skill, knowledge or subjective judgement of the demolition engineer or other individual responsible for a demolition project. Research on demolition ‘process management' is a new area that has rarely been addressed. However, within the building design and construction management sectors, there are a number of intelligent solutions that have been developed to assist in the management of business processes and business process re-engineering. Process management systems and process mapping through the use of Information Communication and Technology (ICT) technology have been applied to help the construction industry significantly improve performance. In an attempt to provide intelligent support to the management of dynamic demolition processes, this research reports upon that was developed using ICT applications a management system prototype entitled “Demolish-IT”. The prototype of Demolish-IT utilises four tiers of information which includes: (1) the standard demolition process map; (2) user-defined demolition process map; (3) demolition task manager; and (4) database of demolition process requirements. The prototype provides on ICT platform that unifies demolition processes and requirements to achieve improved process management. The research involved a combination of face-to-face interviews with demolition experts; real projects document reviews and site observation to produce the generic demolition process map. Other products of the work included: database solutions to store demolition process requirements; and process modelling to manage demolition task compliance flow within relevant industry standards. Evaluation of the research work proved its validity, acceptance and applicability within industry. Future work will aim to transpose the outputs into commercially viable software.
3

3D Map Construction and Data Analysis by LiDAR for Vehicles

Tai, Chia-Hui 03 September 2012 (has links)
Nowadays, LiDAR(Light Detection And Ranging, LiDAR) is the more important and widely applicable measurement technique. The rise of visual system in 3D is very useful to the measurement of LiDAR and gets more importance value for 3D reconstruction technology, in which abundant surface features are implied in the point cloud data. Combined with the image and laser technique for real-time rendering, the LiDAR will be more functional. This thesis proposes and designs a system which combined with Laser Range Finder and 3D visual interface for vehicles, and also equipped with rotary encoder and initial measurement unit to DR(Dead Reckoning) function. Through the coordinate transform method of 2D to 3D, the 3D coordinate of each point will be calculated, and embedded with the color information which captured from the camera to take 3D color point cloud collection. This method is also called Mobile Mapping System(MMS). In addition, this mapping system uses Direct Memory Access technology to display the point cloud synchronous in 3D visual system. Except for the point cloud collection, the reconstruction of point cloud data is used in this system. The surface reconstruction is based on Nearest Neighbor Interpolation method. There are two factors to conduct the interpolation process: the angle and distance between two sample points from the points sequence. The reconstruction of point cloud and calibration of DR is not only to confirm the accuracy of 3D point cloud map but also the ¡§New Geography¡¨ of the 3D electronic map. This research will build up an independent Mobile Mapping System.
4

none

Wang, Han-Chuan 30 August 2004 (has links)
Abstracts Due to an excessive number of companies in the beverage industry, there exist tremendous product differentiation and brand proliferation. Product substitutability and low unit price further lead to severe market competition. Therefore, beverage manufacturers need to constantly obtain detailed and current consumer preference and distribution information in order to enhance promotion and sales of their own products. However, through studying the charts and graphs from marketing and distribution data, there can still be areas of uncertainty and unpredictability.This study uses a case study methodology and conducts in depth interviews with experienced individuals within the beverage industry. Assessment will include their market information processsing abilities. and their participation in developing a computer map support system to increase the effectiveness of marketing and operational units within their corporations. From the interviews with marketing and operation executives, a database application and infrastructure can be used to first organize, analyzd, summarizd, and classify informational data. Then,the resultes can be stored in a database for the use by the computerized map support system. Therefore, this improves upon the system response time and avoids encountering large amoutn of data needing analysis and complex calculations. This database system also needs to be capable of comprehensive data organization and analysis in order to detect market trends and direction, assisting executives in digesting historical data. In summary, the application and utilization of the computerized map support system can be a very useful tool in helping marketing and operation executives in their strategic and decision making processes and needs. This research hopes to utilize the development of computerized mapping support system to assist domestic beverage companies in thoroughly analyzing current market operational insufficiencies. Furthermore, this system can detect strategies of other competitive brands. Through these two analyses, the company will be able to respond rapidly, appropriately and effectively. Computerized mapping support system has the further advantage of detailed statistical computations, data analysis, and early detection of minute market changes. The continued applicaton of the comptuerized mapping system will definitely assist the marketing and operation divisions to better understand market behavior, leading to the goals of achieving better productivity, higher success rate to new strategies, and overall superior competitiveness. KEY WORDS¡GThe Beverage Industry¡BThe Comptuerized Mapping System¡B The Marketing and Operation Divisions
5

A Mapping System as a Method in Experiential Culture Learning and Engagement

Mohammad, Faisal 01 January 2016 (has links)
From my observation as a new resident in Education City, I recognize a need for cultural awareness and communication amongst those studying and working in this particular area. With this project I propose a different experience, a new way to use experiential learning as a mechanism to change people’s predetermined opinions about one another and disrupt personal biases in order to foster cultural awareness and friendship. A mapping system or wayfinding strategy to navigate a new city is the beginning of a visitor’s experience in a new place. This new experience is one way for users to identify locations through the use of a mapping system, discover cultural communication areas and be involved with sensory objects that require them to become aware of their surroundings. All of these elements are a catalyst for students in Education City to communicate and participate in experiential learning as part of their experience in Qatar.
6

A review of the environmental resource mapping system and a proof that it is impossible to write a general algorithm for analysing interactions between organisms distributed at locations described by a locationally linked database and physical properties recorded within the database

Hall, Bryan, University of Western Sydney, Faculty of Science and Technology, School of Science January 1994 (has links)
The Environmental Resource Mapping System (E-RMS) is a geographic information system (GIS) that is used by the National Parks and Wildlife Service to assist in management of national parks. The package is available commercially from the Service and is used by other government departments for environmental management. E-RMS has also been present in Australian Universities and used for academic work for a number of years. This thesis demonstrates that existing procedures for product quality and performance have not been followed in the production of the package and that the package and therefore much of the work undertaken with the package is fundamentally flawed. The E-RMS software contains and produces a number of serious mistakes. Several problems are identified and discussed in this thesis. As a result of the shortcomings, the author recommends that an enquiry be conducted to investigate *1/ The technical feasibility of each project for which the E-RMS package has been used; *2/ The full extent and consequences of the failings inherent with the package; and *3/ The suitability of the E-RMS GIS package for the purposes for which it is sold. Australian Standard 3898 requires that the purpose, functions and limitations of consumer software shall be described. To comply with this standard, users of the E-RMS package would have to be informed of several factors related to it. These are discussed in the research. Failure to consider the usefulness and extractable nature of information in any GIS database will inevitably lead to problems that may endanger the phenomena that the GIS is designed to protect. / Master of Applied Science (Environmental Science)
7

Testování přesnosti mobilního mapovacího systému MOMAS / Accuracy testing of mobile mapping system MOMAS

Nováčková, Soňa January 2012 (has links)
The aim of this thesis is to introduce the mobile mapping system MOMAS, which is owned by Geodis Brno, spol. s.r.o. and test the accuracy of the system. Perform data collection and processing of data in the workplace company Geodis. In addition, identical target points, determine their coordinates and compare them with the coordinates obtained MOMAS system. And finally processed statistically derived coordinate differences.
8

Mobile LiDAR/Imaging Mapping Systems for Lane Marking Inventory

Yi-Ting Cheng (18085930) 01 March 2024 (has links)
<p dir="ltr">Road safety analysis typically relies on the correlation between road surface conditions, lane marking status, or lane width and crash data. Traditionally, this data is surveyed in the field after road construction or car accidents, which is labor-intensive, time-consuming, and hazardous. With the development of mobile mapping systems (MMS) in recent years, the ability to collect lane marking retroreflectivity or lane width information has been greatly improved. By utilizing Light Detection and Ranging (LiDAR) point clouds and RGB images captured by MMS, it is possible to establish lane marking inventory that includes the conditions of pavement markers (such as lane marking retroreflectivity and lane width) for road safety analysis.</p><p dir="ltr">This dissertation aims to develop a comprehensive framework to extract lane markings and report their characteristics using MMS datasets for transportation safety. The proposed approaches include geometric/morphological and deep learning-based approaches based on the LiDAR point clouds acquired by MMS. A normalization strategy is developed to ensure consistent intensity values across laser beams/LiDAR units/MMS for the same objects, thereby enhancing the lane marking extraction. In addition, an image-aided LiDAR approach is proposed to improve the extraction process further. Following the extraction, lane marking classification and characterization, including intensity profile generation and lane width estimation, are conducted to establish comprehensive lane marking inventory.</p><p dir="ltr">To evaluate the proposed strategies, lane marking extraction with and without intensity normalization is also conducted. The results show that the proposed intensity normalization significantly improves the performance of lane marking extraction, regardless of the approach or data used. The geometric approach using normalized intensity achieves F1-scores higher than 90%, outperforming the learning-based models. Furthermore, the intensity derived from two different MMS is compared for performance evaluation, and the agreement of normalized intensity values is within a range of 3.1 to 3.8 (the used MMS provide intensity as an integer number within 0 to 255). Through the normalization, a positive linear relationship between LiDAR normalized intensity and retroreflectivity is found, with the strongest relationship providing an R<sup>2</sup> of 0.72 and a Pearson's correlation coefficient of 0.85. A comparison of the correlation between original/normalized intensity and retroreflectivity revealed a stronger correlation between original intensity and retroreflectivity. For image-aided LiDAR approach, the image information indeed enhanced the LiDAR-based lane marking extraction approach, as evidenced by the highest F1-score (92.5%) of the image-aided LiDAR approach, outperforming the LiDAR-based (90.3%) and image-based (77.8%) ones. Specifically, the recall increases by 4.0% – from 87.6% (LiDAR-based) to 91.6% (image-aided LiDAR) – surpasses the slight improvement in the precision of 0.2% – from 93.2% (LiDAR-based) to 93.4% (image-aided LiDAR).</p><p dir="ltr">Finally, a Potree-based web portal is developed to visualize the results derived through the proposed lane marking extraction/classification/characterization strategies. This portal includes a function that enables the projection between 2D images and 3D point clouds, as well as tools for displaying intensity profiles and lane width estimates. It is capable of rendering a large dataset of {approximately 4.2 billion LiDAR points} in around ten seconds and allows for the visualization of intensity profiles and lane width estimates. Users can select points of interest in an intensity profile/lane width plot. This selection will result in the corresponding point being showcased in the LiDAR data on the web portal. Furthermore, the LiDAR point can be projected onto the corresponding image.</p><p dir="ltr">The above proposed strategies facilitate the investigation of the relationship between LiDAR intensity and mobile retroreflectivity. To ensure quality control, lane markings derived from geometric and learning-based extraction approaches were compared. These strategies were evaluated using two MMS (equipped with multiple imaging and LiDAR sensors), covering extensive road segments exceeding 400 miles. Furthermore, a reporting mechanism based on multi-modal data from various MMS sensors was implemented to visualize the results derived from the proposed strategies and to serve as a quality control tool. Consequently, the proposed strategies are easily adaptable for different MMS or the regular updating of lane marking inventory.</p>
9

Qualification et amélioration de la précision de systèmes de balayage laser mobiles par extraction d’arêtes / Edge-based accuracy assessment and improvement of mobile laser scanning systems

Poreba, Martyna 18 June 2014 (has links)
Au cours de ces dernières décennies, le développement de Systèmes Mobiles de Cartographie, soutenu par un progrès technologique important, est devenu plus apparent. Il a été stimulé par le besoin grandissant de collecte d'informations géographiques précises sur l'environnement. Nous considérons, au sein de cette thèse, des solutions pour l'acquisition des nuages de points mobiles de qualité topographique (précision centimétrique). Il s'agit, dans cette tâche, de mettre au point des méthodes de qualification des données, et d'en améliorer sur les erreurs systématiques par des techniques d'étalonnage et de recalage adéquates.Nous décrivons une démarche innovante d'évaluation de l'exactitude et/ou de la précision des relevés laser mobiles. Celle-ci repose sur l'extraction et la comparaison des entités linéaires de la scène urbaine. La distance moyenne calculée entre les segments appariés, étant la distance modifiée de Hausdorff, sert à noter les nuages par rapport à des références existantes. Pour l'extraction des arêtes, nous proposons une méthode de détection d'intersections entre segments plans retrouvés via un algorithme de RANSAC enrichi d'une analyse de composantes connexes. Nous envisageons également une démarche de correction de relevés laser mobiles à travers un recalage rigide fondé, lui aussi, sur les éléments linéaires. Enfin, nous étudions la pertinence des segments pour en déduire les paramètres de l'étalonnage extrinsèque du système mobile. Nous testons nos méthodes sur des données simulées et des données réelles acquises dans le cadre du projet TerraMobilita. / Over the past few decades, the development of land-based Mobile Mapping Systems (MMS), supported by significant technological progress, has become more prominent. It has been motivated by the growing need for precise geographic information about the environment. In this thesis, we consider approaches for the acquisition of mobile point clouds with topographic quality (centimeter-level accuracy). The aim is to develop techniques for data quality assessment and improvement. In particular, we eliminate the systematic errors inherent to an MMS data using appropriate calibration and registration methods.We describe a novel approach to assess the accuracy and/or the precision of mobile laser point clouds. It is based on the extraction and comparison of line features detected within the urban scene. The computed average distance between corresponding pairs of line segments, taking advantage of a modified Hausdorff distance, is used to evaluate the MMS data with respect to a reference data set. For edge extraction, we propose a method which relies on the intersections between planes modelled via the RANSAC algorithm refined by an analysis of connected components. We also consider an approach to correct point clouds using a line-based rigid registration method. Finally, we study the use of line segments for estimating the boresight angles of a land-based mobile mapping system. We apply our methods to synthetic data and to real data acquired as part of the TerraMobilita project.
10

Mobilní mapování / Mobile Mapping

Manda, David January 2013 (has links)
The aim of this thesis is introduce the mobile mapping system IP-S2, which is using by company GEODIS BRNO, and perform data collection by this system. Measure the identical points, determine their coordinates and compare with coordinates obtained by mobile mapping system. The conclusion of this thesis is focused on testing the accuracy of the mobile mapping system.

Page generated in 0.0716 seconds